Tag Archives: design

Borgundian Mechanized Infantry Loadout

Let’s get this started. I’m following my own challenge rules, which you can find here. We’ve made a bunch of decisions so far, so let’s get those out of the way. Oh, and all weights are going to be in pounds, because I’m an American. Divide by 2.2 to get weights in commie kilos.

Carbine: HK 416. I didn’t specify a barrel length preference then, but we’ll go with 14.5 inches. Comes to 7.69 lbs empty. We’ll also need ammo in that gun. Thirty rounds of 62 grain M855A1 or similar in an aluminum, 30 round magazine comes to 1.06 lbs. Per doctrine, we’ll need a suppressor and an optic. We’ll take an Aimpoint Comp M4 red dot (0.74 lbs with mount and killflash) and a Surefire 556RC2 suppressor (1.06 lbs.). Also, we’ll need an IR laser/illuminator, because battles don’t stop at night. My choice there would be the B.E. Meyers MAWL-DA. I don’t have a weight for this, so I’m going to guesstimate 0.5 lbs based on other, similar devices. Plus a sling, which is going to set us back about another quarter pound. All of that adds up to 11.3 lbs, which is kinda sucky, actually. Oh well. Lots of capability there, not much to be done about it. Quit complaining and drop and give me thirty.

Armor time. See here for why I picked what I picked. IOTV (and we’ll add the deltoid (fragmentation) protectors, but not the side plates) is 26.69 lbs for a size medium. Size medium ECH is three pounds. Ballistic Eyewear adds 0.15 lbs, foam earplugs add 0.1 lbs, and knee and elbow pads add another 0.4 lbs. An FM50 gas mask rounds out the protective equipment list, adding another 1.85 lbs. Total weight for protective gear is 32.19 lbs.

Ammo. Pretty straightforward. Six spare thirty round magazines. Two M67 frag grenades. And two smoke grenades. Something like the M18, but with added thermal obscurants. Six mags comes to 6.36 lbs, two M67s comes to 1.76 lbs, and two M18s comes to 2.38 lbs, for a total ammo load of 10.5 lbs. Which doesn’t seem like a lot, but remember the vehicle holds more.

On to comestibles. I’ll go into more detail on this elsewhere. Since these are mechanized infantrymen, they have a big armored vehicle to move them around and carry stuff like food and water in reasonable quantities. Only the essentials need to be carried. For the standard, temperate European operating environment, we think two liters of water is an adequate amount to carry on the person, and we can top this off as needed from the vehicle stores or resupply. For food, we really only expect the soldier to carry an iron ration with him. This will take the form of something like the US military’s First Strike Ration, which is a hot-pocket-like sandwich that supplies the calorie and nutritional needs for one battle day. A full two-liter camelbak-type1 bladder is 4.88 lbs, and a First Strike Ration is 1.95 lbs, bringing total comestible weight to 6.83 lbs.

There are a few other items we need to list out. There’s the IFAK, the Individual First Aid Kit. This is for two reasons. First, it means a soldier can perform some first aid on his buddy. Second, a medic can always find some basic supplies (tourniquet, pressure bandage, sterile gloves) when he needs them in a pinch. Add a pound. We also need to issue a knife. For knife fighting duties, I’d like a double-edged knife, like the Gerber Mk. II. However, most knife tasks are utility tasks for the modern soldier. For these, a tough single-edge knife will work better. Something like a Ka-Bar. Tough, effective, legendary. I have one and love it. Add another 1.23 lbs for a Ka-bar and sheath. And we’ll need some night vision kit. I’ve been going for the high-end, feature-rich stuff. No sense in stopping now. We’ll take the PSQ-20B, which gives us third generation image intensifying optics plus thermal optics in one rugged, two pound unit. At least the battery pack is detachable and can be affixed to the back of the helmet for balance. Finally, we’ll need a radio. The PRC-159 from Harris should do nicely. Compatible with the once and future frequencies, plenty of encryption, good battery life. With battery, it weighs 1.72 lbs.

Almost done, I swear. The standard poncho with liner is a really great piece of kit. It’s waterproof, surprisingly warm, and extremely packable. That’s my one concession to weather that might crop up unexpectedly. Obviously, coats are worn when you can expect bad weather, like say in the winter. 1.5 lbs for the poncho and liner. And we’ll add a multitool, because they are ridiculously useful little things. 0.6 lbs for that.

Let’s wrap up by looking at what we’re not issuing. Recall that this is a regular rifleman. He is not a squad leader. Therefore, he does not usually need navigation equipment so he does not have a lensatic compass, maps, or a portable GPS receiver as a matter of course. He might be given these things as part of a specific mission, and that’s fine. Spare batteries for the various electronic devices mentioned are carried aboard the vehicle normally. As a side note, just about all the devices here take AA batteries. Logistical commonality strikes again!2 Similarly, cleaning kits are generally expected to be carried aboard the vehicle. as are entrenching tools. Further, since they aren’t on soldier’s backs, we can issue full size picks and spades, not the lame folding versions.

All-up weight for our kit is 68.87 lbs. Which is on the heavy side, but about on par with other modern armies. Remember, the pack is normally left in the vehicle, so it’s not counted in the fighting load.

1.) I actually prefer the Source brand bladders.
2.) Did you expect anything different from me?

Design Compromises: A Case Study

Every design is a compromise. There are no free lunches. And trying to work out the why can be very informative. So let’s take a look at one of my favorite tanks, the M1 Abrams, and look at some design compromises, and their results. Since it’s very nearly equivalent, and designed at about the same time, I will use the Leopard 2 as a point of comparison. The Leopard 2 is somewhat more conventional internally in a few subtle ways.

The most obvious difference is the engines. Both designs have 1,500 hp engines, but where the Leopard 2 uses a pretty conventional twin-turbo V12 diesel, the Abrams uses a gas turbine. This gives the Abrams better acceleration, but also necessitates a greater internal fuel capacity. Where the Leopard 2 can get away with 1,200 L of fuel stowage, the Abrams needs about 1,900 L to meet its (shorter) range requirements. More fuel means more space. We can note that the Abrams has fuel tanks on either side of the driver, in addition to in various other places. The Leopard 2 does not have fuel stored up front in the hull.

The hull front on the Leopard 2 is used to store ammo in a pretty conventional rack. There’s not much in the way of blast venting provision here, so a penetration would be extremely bad news. That said, this is a pretty common place to store reserve ammo1, and hull hits are much less likely than turret hits. Still, from a survivability perspective, this is clearly not ideal.

The Abrams designers were able to shoehorn a few (six 120mm rounds, more of the smaller 105mm rounds) into a compartment aft by the engine, because of the shape of the gas turbine power pack. This rear ammo compartment has blow-out panels and a heavy door to isolate it from the crew compartment, but it’s not a lot of reserve ammo. The Abrams carries the vast majority of its ammo in the turret bustle. On the one hand, this makes subdivision easy. It’s a simple engineering exercise to add blow-out panels to the bustle, and this makes the Abrams among the most survivable tanks in the world.

Storing 34 120mm rounds in the bustle has its disadvantages. It forces a wide turret. Turret height is determined by the desired maximum gun depression, and a wide, tall turret means the armored volume is correspondingly large. The Abrams has considerably more armored volume than the Leopard, both in relative terms (i.e. crew space), and in absolute terms. Because so much of the Abrams’ ammo load is in the turret, there’s a significant amount of armor protecting the side of the turret bustle. More volume means it takes more weight to provide the same level of protection. Or, you have to use more expensive exotic materials (like depleted uranium).

On the other hand, more internal volume is another survivability gain. Armor penetrations are less likely to cause significant casualties or destroy enough systems to score a mission kill simply because there’s more volume to deal with, and volume leads to dispersion, which is the enemy of the shaped charge jet.

To be honest, on these grounds I prefer the survivability over protection. Protection can be added, but it’s much harder to do a redesign in favor of survivability.

We can see another difference in the guns on the latest models. Since the M1A1, the Abrams has been equipped with a license built Rheinmetall 120mm/L44 gun, just like Leopard 2s up to the A5 model. Subsequently, the Germans went to a longer L55 gun for more penetrating power. The Americans have not. So what gives?

Recall that Americans like their depleted uranium. The Germans don’t. Something something environment or something. Anyway, depleted uranium makes awesome armor. It also makes awesome armor piercing rounds. The Americans have done a good job of sinking plenty of R&D funding into new depleted uranium APFSDS rounds. They’re up to a fifth iteration of the design with the M829A4 round. So when adapting a longer barreled gun proved more costly than anticipated in the 90s due to stabilization issues, the US Army quietly dropped the project and stuck with their fancy rounds.

I don’t know if the Leopard 2 didn’t have the same stabilization issues as the Abrams with the longer gun, or if the Germans were just unwilling to change round composition. Regardless, the Germans adapted a longer gun. It means they can use tungsten-based APFSDS rounds, but it also means they will have somewhat more restricted mobility in urban environments.

For this one, six of one, half a dozen of the other. I’m indifferent here, provided both are available. I do wonder if the DU rounds will also perform better in the L55 gun, or if they’re optimized for the L44.

I suppose I should also comment on the engines. I strongly suspect that the Germans made the right choice here with the conventional V12 diesel, though I would strongly prefer an air-cooled model like the AVDS-17902. It’s possible the gas turbine just hasn’t gotten enough development funds, but a diesel engine company can push research into the civilian sector to recoup costs there, in addition to the military. I also approve of forward fuel tanks, and don’t approve of forward ammo stowage. Remember, well-designed fuel tanks provide reasonable supplemental protection.

1.) It’s also used on the Leclerc, K2, and Challenger 2, among others. Doesn’t mean I like it.
2.) Early versions powered the M60 Patton, and the 1,200 hp variant powers the Namer. A 1,500 hp variant is available.

Toxotis Self-Propelled Howitzer

Okay, so we have our new MBT, and our new Heavy IFV. Now we’ll outline our self-propelled howitzer. Again, we’re going to make logistics and crew safety a priority. We’re going to push the envelope a bit, but not too much. This will of course be a 155mm howitzer. Can we add another standard item, our stock heavy vehicle engine?

We might think no, at first. 1,500 horsepower is an awful lot of horsepower. But we’re getting pretty heavy. The Panzerhaubitze 2000 and 2S35 Koalitsiya-SV are both about 55 tonnes. That’s pretty close to the weight of our tank, and we can always govern the engine down a bit. So it will be a heavy vehicle, to no one’s great surprise. It will be able to keep up with an armored thrust, of course. The powerpack is rear-mounted.

Heavy is good though. It lets us haul plenty of ammo, which lets us sustain proper fire missions. If there’s one thing I’ve learned from watching The Great War’s wonderful week-by-week of World War One on youtube, it’s that there’s no such thing as enough artillery shells. Artillery does the killing. Artillery is the key to success.

But, a good load of artillery shells (which are, of course, explosive) and the charges needed to launch them (more explosives, duh) is going to be dangerous in the event of an armor penetration. To maximize survivability, we will take a page out of our MBT design and completely separate the crew from the ammunition.

This means a reduction in crew, because we can’t have human loaders. We’ll need to handle loading shells and charges automatically. This is a little harder than it was in the Myrmidon, since tanks use convenient one-piece ammo. So the projectile and cartridge and primer are all in one relatively easy to handle piece. Great. But artillery is different. Artillery has a much larger range spectrum than an MBT gun, because it’s an indirect fire weapon. To make accommodating this easier, charges come separate from the projectiles, and in different sizes. Recently, rather than dealing with a whole bunch of different size charges, some have developed modular charge sets, to let you build a full charge from smaller, easier to handle bits. To no one’s great surprise, we’ll go with this. Specifically, the Bofors Uniflex-2 Modular charge system, since it’s already developed. As a bonus, Uniflex-2 charges are insensitive munitions, so they’re harder to accidentally detonate. Which is great for reducing how bad an accident gets. Electrical fires suck. Electrical fires setting off your stowed ammo load sucks more.

To maximize the potential of the Uniflex 2, we’ll have a chamber volume of 25 L on our 155mm/L52 howitzer. This is a bit bigger than the NATO standard of 23 L, but that’s not really a big issue for us. We can still use NATO standard projectiles, which is the more important bit, since that saves us some R&D money if we can just buy/license existing things like the wonderful GPS-guided Excalibur round. More on exotic and cool 155mm rounds later in this piece. Also, since I know you’re curious, it requires 6.5 Uniflex-2 charges to fill the chamber completely. There are both “full” and “half” size charges, and you need six full-size charges and one half-size charge to fill the 25 L chamber to capacity.

Speaking of capacity, you’re probably wondering how many rounds are carried. The Toxotis carries 60 rounds and associated charges (390 equivalent charge loads total) in two 30 round/195 charge magazines. The magazine subdivision, with corresponding roof blow-off panels, is designed to try to reduce the chance of one hit igniting everything. Ammunition handling, charge loading, fuze setting, and primer handling are all fully automated.

Automatic loading and a modern, computerized fire control system allows for nine-round MRSI1 capability. Toxotis can come to a halt and fire the first shot within thirty seconds of receiving a fire mission. It can get moving again in under thirty seconds.

Electronically, the Toxotis has a fully-computerized fire control system, and our standard friendly unit tracking system. It also has a highly precise navigation suite, which can compute position based on inertial references, from satellite data, or pull in positional information over the tracking system. Fire missions may be computed internally or sent via secure datalink. The radios are designed to facilitate communication with nearby infantry, armor, and aircraft to coordinate support and fire mission requests. So while it can use a fire direction system, this is not required for a fire mission. Like on the Myrmidon, the three-man crew of the Toxotis are all in the front of the hull in an armored capsule. There is, of course, less armor than on the Myrmidon. NBC protection is, of course, standard. There’s also provision for direct fire missions, with a thermal viewer and laser rangefinder mounted on the roof.

To resupply, troops can manually load projectiles and charges into loading hatches at the rear on each side of the turret. These automatically stow the munitions appropriately. For more rapid resupply, the companion reloader vehicle, the Hypaspist, can be used. This is built on a nearly identical chassis to the Toxotis, but it lacks the gun, the rotating turret, and only has a crew of two. In place of the gun is an enclosed resupply conveyor to reload the Toxotis through a hatch on the back of its turret. From here, both magazines can be reloaded. The Hypaspist carries a double-load, or 120 rounds plus associated charges and primers. All ammunition handling within the Hypaspist is fully automated.

Both the Toxotis and the Hypaspist come equipped with a Trophy active protection systems, an array of smoke-grenade dischargers, and a 12.7mm M2A1 heavy machine gun in a remote weapons station on the roof. They are designed for the highest paced shoot-and-scoot missions in mobile warfare. Each weighs approximately 60 tonnes, and the production cost for the pair is $6 million.

Let’s also talk about some off-the-shelf artillery rounds. A standard HE round weighs 43.5 kg, and carries 11.3 kg of HE filler. There’s the M549A1 rocket-assisted HE shell, which has 6.8 kg of HE filler and a rocket motor for extra range. The M110A2 White Phosphorus round, which can be used for incendiary effects or producing smoke, weighs 44 kg, of which 7.1 kg is white phosphorus filler. We have projectiles that can be used to scatter small mines. The antipersonnel variant weighs 46.7 kg, and holds 36 antipersonnel mines. Each mine weighs 0.54 kg, and contains 21.9 g of high explosive. The anti-vehicle variant also weighs 46.7 kg, and holds 9 anti-vehicle mines. Each of these mines weighs 1.8 kg and contains 0.6 kg of high explosive. There’s also a couple submunition variants available. The standard version holds 88 dual-purpose (antipersonnel/antimateriel) submunitions. The extended range version has a base-bleed shell, and holds 72 dual-purpose submunitions. The submunitions are similar to the US DPICM submunitions.

In terms of smart rounds, several more are available on the market at present. There’s the long (1.4 m), heavy (62.4 kg) M712 Copperhead, which uses laser guidance. This provides useful capabilities against quickly identified point targets, including armor. Also available for the anti-armor mission are the very similar Bofors BONUS round and the Rheinmetall SMArt 155 round. Both have a pair of smart submunitions that fall slowly in a spiral pattern. Multispectral infrared sensors and a millimeter wave radar are used to detect armor targets. If one is detected, the submunition fires an explosively-formed penetrator at the target. Finally, there’s the aforementioned M982 Excalibur, which is GPS guided. For fixed targets, this is easier to use than a laser-guided round like the copperhead, since it doesn’t require a designator, but it is not useful against moving targets.

1.) Multiple rounds, simultaneous impact. So the Toxotis can fire up to nine rounds at a target and have them all hit at the same time, totally ruining someone’s day.

So make yourself an ARK: ragging on the platform

Not very hard, I admit: I’ll grant you that the AR-15 is an excellent example of a weapon design which is easy to work on, easy to assemble, and easy to maintain. As far as building your own goes, the AR-15 is a lot like democracy: the worst system, except for all the other ones we’ve tried.

That being said, though, no other rifle has the same reputation as the AR-15, whose marketing says that any enterprising citizen with some tools in the basement can knock one together from your various parts kits. This is technically correct, and while I’m on the record saying that technically correct is the best kind of correct, I have to throw the flag here, for two separate reasons.

First: the AR-15 in its original design does require specialist tools, to attach a pinned gas block. Fortunately for modern end users, set screw and clamp-on gas blocks are much more popular, because they, y’know, work just as well. If you build to the original spec, you need a drill press, which brings us to…

Second: the fairer comparison is an 80% AR lower against an 80% AK blank. You’ll need a drill press for the AR lower as well as the AK blank; there’s just less of a market for AK building because it doesn’t have that Lego feel.

Beyond that, the AR has a ton of annoying fiddly bits which, while still better than, say, rivets, are still a pain. Consider the barrel nut. Rather than having a single purpose and a single torque specification, it has two purposes and a massive torque range: it holds the barrel to the receiver, and it supports the gas tube through its notched flange while being locked in place by same. This is an example of too-clever-by-half thinking. The barrel nut ought to just be a regular nut, and when designing a regular nut, it’s best to rely on torque over some external device designed to inhibit the rotation of the nut. If the gas tube needs support, design a separate part for that.

Consider also the roll pin. Sure, it does its job, but at what cost? In most cases where I may want to remove a part, I prefer set screws or mechanically-retained pins. (Remember, I have c-spring retained trigger and hammer pins on my lower receiver.) I will grant that the roll pin is fine in some places. For instance, I don’t intend to ever replace the trigger guard on my lower receiver, so roll pins are fine! Similarly, I don’t plan on unpinning the gas tube from the gas block; if I have to replace one, or if I want to change one, I’ll replace them as a unit. Same deal: roll pins cool.

Parvusimperator asked me to gripe about the dust cover, but I (intelligently) bought an upper receiver which already has the dust cover installed.

The worst part is that most of these failings need not be failings! It’s dead simple to make an AR-15-compatible receiver. Upper receivers especially already exist to meet a myriad of needs. Why not improved end-user serviceability? Lowers are a harder pill to swallow, since ‘needs special parts’ is a terrible thing to see on the side of one. Then again, ambidextrous lower receivers are a thing, and most end users are only going to bother changing furniture, triggers, and maybe buffers, none of which are big offenders in the special-tools market. The same reasoning holds here. We already have specialist AR-15 lowers for the ambidextrously-interested. Why not for the bolt-catch-replacingly-interested?

So make yourself an ARK: 7.62×39 AR reliability

In a previous post, I alluded to the canonical article on AR 7.62×39. That is this article, an excellent resource by a guy who goes by Major Pandemic1. It identifies two issues with AR functioning in 7.62×39 rifles: cycling, which I will use to mean exclusively the movement of the action, and feeding, which I will use to mean the process by which ammunition is stripped from the top of the magazine and pushed forward into the chamber. These two issues are, at their base, related, and Major Pandemic hits upon the solutions pretty quickly, along with one which I believe to be superfluous. This is because he hit them in the wrong order.

It’s impossible to claim an AR-pattern rifle is unreliable without first making sure the gas system is functioning as designed. Thanks to parvusimperator’s recent book acquisitions on and general encyclopedic knowledge of the history of the scary black rifle, I have a few instances to cite. First on the list are the M16 and M16A1, where a change in powder from stick-type to ball-type yielded a change in pressure curve. The result: unreliable functioning2. Rounding out the list are your various carbines, from the CAR-15 in the 1960s and 1970s to the M4 carbine through to the super-short Mark 18/Close Quarters Battle Receiver, all of which fall prey to another issue: changing the barrel length without changing the gas system. When you shorten (or lengthen) a barrel, you decrease (or increase) the dwell time. That figure, the measure of how long a bullet stays in the barrel (and barrel pressures remain high), combines with the pressure curve to determine where the gas port should be placed, and how large the gas port ought to be.

Fortunately for 5.56 NATO shooters, the hard work has already been done, and barrel manufacturers have the sizes and locations pretty much figured out. Unfortunately for we 7.62 Russian Short shooters, the same body of work is not yet done, and shooting a different cartridge with a vastly different pressure profile is the very definition of messing around with the gas system. When doing your function tests, be prepared! If you run into cycling issues, try a lightweight buffer and/or a lightweight spring. (I believe the received wisdom is to try them in that order. Parvusimperator will correct me, if not.) If that doesn’t suffice, you may have to increase the size of your gas port. With a drill, I mean, and a bit. Don’t increase the size too fast: my 7.62 AR functions perfectly with a factory gas tube size of about 1/12″. If you get to larger than 1/8″, you’ve almost certainly done something else wrong. A bluing pen (if you’re using a blued or nitrided barrel) should give you some finish around the gas port.

Next, and obviously, get dedicated magazines. The 7.62×39 cartridge is obscenely tapered, and only magazines specifically designed for it will push your cartridges up in front of the bolt carrier proper-like. This isn’t .300 Blackout; it’s not shaped anything like a 5.56 round, and any magazine not designed to feed 7.62×39, in a word, won’t. Midway’s AR-Stoner brand works well, and they won’t break the bank.

That brings us to feeding issues. By this point, you shouldn’t have any. If you clicked through to Major Pandemic’s article, you’ll see that he decided to dremel out the divider between the feed ramps. Granted, Bushmaster’s successful, functional 7.62×39 AR took the same tack, but my suspicion is that they made the same mistake other manufacturers, plus innumerable individual builders, made: an undergassed or overbuffered gun leaving magazines insufficient time to fully feed the next cartridge before the bolt carrier returns.

If and only if you simply can’t get your rifle to function correctly, you may consider a few courses of action before breaking out the dremel. Different magazines may help. It’s a bit of a shame that you may have to match a specific brand of magazine to your rifle, but if you were expecting rock-solid reliability with any equipment you care to find, you should have bought an AK. You might also try shooting it more. There’s a break-in period to any gun, and springs and lubrication may not take at first. If you do resort to dremeling and you have a barrel with a finish, don’t forget the wee touch-up pen to get your corrosion resistance back.

I think I’ll close with one final note on barrel selection. Faxon Firearms, who I’ve mentioned before, seem to make an excellent product with a gas port able to run just about any example of our favorite Russian intermediate cartridge without issue. I recommend their product. If you ignore that recommendation, I would at least suggest you look for a nitrided/Melonited barrel. Nothing else really makes sense for 7.62×39: presumably, you’re going to want to shoot cheap steel-cased, bimetal-jacket ammo, and a harder barrel helps to offset the additional wear you get from that choice. Combine that with the much lower velocities you have to work with compared to 5.56, and you may be surprised at the barrel life you end up with.

Then again, you may not. As you may have noticed, we don’t have sponsors around here, so I’m engaging in the most rampant of rampant speculation, not being able to afford 1) a second barrel to beat up and 2) the 20,000-40,000 rounds of ammunition it would likely take to really blow the first item out. As always, we’re curious about your experiences with 7.62×39 ARs, dear reader, so leave a comment if you have any.

1. I’m hardly one to talk about strange monikers, though.
2. I found some rather morbid documented accounts of US soldiers found dead next to malfunctioned, torn-down M16s, suggesting the men were killed while trying to fix their rifles.

I would very strongly recommend messing with buffers, buffer weights, or even a reduced mass bolt carrier before touching the buffer spring. There are plenty of options out there to reduce the mass of the operating components if you want to go that route. Clipping spring coils is a good way to get plenty of malfunctions. -parvusimperator

Rampant speculation: why did the Falcon 9 blow up?

I am not a rocket scientist, but I do like to think about engineering problems.

Here are the facts as we know them:

  • A Falcon 9 rocket blew up on the pad on September 1, 2016.
  • The rocket was undergoing a pre-launch static test, when it exploded.
  • According to SpaceX, the explosion originated in the second-stage liquid oxygen tank.
  • SpaceX uses a fancy super-cooled LOX mix, which allows more fuel in a given tank volume, which allows better performance.
  • Last summer, SpaceX had another rocket fail. The CRS-7 mission disintegrated in flight after the upper stage LOX tank burst. The internal helium tank (to maintain tank pressure) failed because of a faulty strut.

Now, for a rocket to fail during fueling, before engine firing—as the most recent Falcon failed—is very unusual. To my engineer’s mind, it suggests a materials problem in the LOX or liquid helium tanks, something failing in an unexpected way when deep-chilled. Crucially, the Falcon 9’s LOX tank experiences the coldest temperature (for a LOX tank) in the history of rocketry. Take that in combination with the failure on the CRS-7 mission: after their investigation, SpaceX switched to a new strut, which means new failure modes.

Mark my words (and feed them to me along with a heaping helping of crow, when I turn out to be wrong): this is another strut issue, be it faulty or just unsuited for the deep-cryo fuel in some other way.

Mechanized Infantry Platoon 2: Experimentation

Now that I’ve hit my monthly quota of Obvious Fishbreath Provocations, we can get back to our regularly scheduled theory posts.

I’ve talked about these before, and that was fun. Of course, that posited a CV9035 with eight man capacity. As you’ll recall, my original choice of IFV was for the Puma, with a capacity of six, and I’ve gone back and forth since. Besides, CV90s tend to get uparmored and loaded with stuff, with reduced capacities of seven or even six men. But let’s get back to the Puma. I’m still fond of it, and it’s still the best protected actual IFV in the world. It doesn’t really need to worry about RPGs of any type or DPICM-type bomblets. Yay. And it’s going to take the least amount of fussing to get the design pretty close to where I want it. At least, if I can get over the dismount capacity. So, what if we damned the cost (or accepted GAO’s estimates, which seem reasonable), and built our mechanized infantry platoon (‘Zug’ to you Germans out there) around the Puma?

We’re stuck with a six-man dismount capacity in the Puma. No changing it. We can get three eight-man squads with four Pumas. I think it might be easier to think of these as four smaller ‘squadlike units’ though, where each vehicle and its dismounts is considered a “squad.” At least for planning purposes. The infantry in the field can organize as they like. Thinking this way gives us a basis of issue of ‘per man’, ‘per vehicle’, and ‘per platoon’, which is awfully convenient. And it encourages improvisation. I’m beginning to think that on-paper squad organization doesn’t really matter too much, since there are so many good enough answers out there. And it is unlikely the platoon will be at full strength, anyway. So I’ll settle for a convenient planning conceit, and let the men in the field sort stuff out. They’ll certainly have enough firepower.

Further, there are many reasonable organizations for 24 men, and four vehicles is a nice cost/dismount balance. There are another twelve men who are vehicle crews, bringing our total platoon strength to 36 men. It is assumed by me that three of the four vehicle commanders are the platoon headquarters component1, though they can take which seats they like. I will also assume the fourth vehicle commander, plus the four gunners and the four dismount team leaders, are some flavor of NCO. The rest of the platoon can be whatever rank, but there’s our on-paper minimum NCO staffing level.

There’s a bunch of stuff that is issued on a per-man basis. Of biggest note to you, I’m sure, are: the helmet, the standard protective vest (which I’ll discuss elsewhere), and the carbine. Dismounts get a fixed-magnification optic.2, plus sling and NVG-compatible aiming laser3. Dismounts also get a night vision monocular4 and a radio (specifically the SRX 2200) to communicate amongst themselves if separated. The dismount element leader additionally gets a PRC-148 radio to communicate with other elements of the platoon, and a handheld GPS receiver (the PSN-13). Vehicle crews are issued an Aimpoint Comp M4 red dot and sling for their carbines. I won’t discuss ammo or numbers of grenades or number of rations here. There are lots. I chose a capacious IFV deliberately to let me haul things. How many? Shut uP. The P is for Plenty.

Before we get to vehicle-issued stuff for the men, let’s refresh our memory on the Puma. The Puma is armed with a 30 mm autocannon, a 5.56 mm machine gun, and a twin-tube launcher for the Spike LR. The Spike Launcher still hasn’t been seen on Pumas in the Bundeswehr, or at least, not in the pictures I’ve seen, but it is fitted to all of the various Lance turrets flavors that are out in the wild. So I’m stipulating it. The fittings are there. Additionally, the Bundeswehr Pumas have a 5.56 mm coax machine gun. Presumably this was to make weight for the A400m, and because of the stowed kills argument. Alternatively, I’ve heard space in the turret might be a problem. Anyway, I’d really like to see the stowed kills argument analysis, and if you could fit a 7.62 mm MG in the turret. I’m not convinced you couldn’t make one fit. To keep things simple, we will stipulate that the caliber of the coax match that of the dismount MG. So, for now, let’s assume it’s the 5.56 mm MG4, since that’s what’s in the design, and I’m trying not to go nuts with changes. COTS, remember? If the 7.62 mm coax is preferred after the above tests (and perhaps a blogpost of thought experimenting), give the dismounts the Negev NG7 accordingly. Of course, since the Puma does carry plenty of 30×173 mm rounds, we can use those against targets too tough for the 5.56. I think we’ll also see an increasing number of up-armored soft vehicles that would resist 7.62×51 mm just as well as the 5.56 stuff, so the difference may not be of concern in the future.

Anyway, each vehicle has an MG4 mounted in the turret as a coax weapon. Each vehicle has a second MG4 for the dismount team. Note that the dismount machine gunner also has a carbine available should he need it. This will help for building clearing. Again, each machine gun has a fixed power optic, a sling (with extra padding), and another of those night-vision-compatible laser sighting units. Note that the vehicle coax and the squad can share belts of ammo. And, only one kind of belted ammo has to be supplied to the platoon. We’re also keeping the number of belt-fed weapons down to keep the number of riflemen up in the platoon and “squad.” We still have machine guns in the vehicles. Plus, tests have shown that if a squad has multiple machine guns, it’s a lot harder to keep it in the fight as it takes casualties.

As noted above, the Puma carries a launcher for two of the excellent Spike-LR ATGMs. These are rather heavy. We’ll figure that each vehicle should carry at least two additional Spike-LRs, plus a tripod and command launch unit should the dismount team wish to use them, perhaps in an ambush. The weight of the Spike-LR and launcher is quite heavy, so we also figure that this is not going to be lugged around very much. Additional, somewhat lighter antitank capability, at ranges more in line with those of the rest of the dismount element’s weapons, is provided by a Panzerfaust 3 launcher, Dynarange sighting unit, and at least three Panzerfaust 3 rockets. Most of these should be the newer PzF3T rockets with tandem warheads, but the PzF3B demolition round is also very useful. In both cases, more rockets and missiles is better, but the above should provide a reasonable baseline. Additional disposable rockets like the M72A7 or the AT4 can be provided as needed. The Puma has plenty of storage space.

Each vehicle is also provided with a 40 mm underbarrel-type grenade launcher (e.g. the M320) and some grenades. I do love high explosives. Field reports seem to indicate that soldiers prefer having these with the little stock units attached, so their rifle isn’t super heavy most of the time. So let’s provide a stock unit with each grenade launcher. The option for independent use is there.

On to things issued at the platoon level. Distributed amongst the platoon is the following supplemental hardware: the PRC-150 manpack radio, two LGI F1 spigot commando mortars, and two 7.62 mm marksman rifles.5 The manpack radio provides a backup option for communication, useful if separated from the vehicles. The LGI F1s are easy for a single man to use, and give us some indirect fire options. Much cheaper and more convenient than that lame XM25. Plus, it actually works. Finally, the marksman rifles give us an option for a bit of precision at range. These items can be divvied up amongst the vehicles as desired.

So there we have it. I like this. I didn’t specify a table of equipment in my previous platoon post, so let’s compare with some real-world examples. I’m giving up two machine guns when compared to the standard US Army Mech platoon, and three 40mm grenade launchers. I have the three Panzerfaust 3s and two LGIs, which gives me some platoon level indirect fire and some very heavy HE projection. Coordination abilities should be similar. I also have the 7.62 mm rifles at the platoon level, which give some extra reach if desired. I’m taking a page or two out of a Russian Motorized Rifle Platoon book. The American squad has a Javelin, plus the Bradley has some TOW missiles. I’ve got a similar long range guided antitank punch in the Spike LR missiles. And I’m similarly high tech, with plenty of comms in the above table. One other thing I like is that the above TO&E is pretty adaptable to any other IFV I might choose to design around, including the Bradley, the CV90 (even the versions with fewer dismounts), or the ASCOD.

1.) I.e. Platoon Leader (a lieutenant), Platoon Sergeant, and Platoon Guide (another sergeant).
2.) E.g. an ACOG. I might go with a HAMR or SpecterOS though. Regardless, fixed 4x optic. I should write a blog post on this.
3.) E.g. PEQ-15, but I might find one I like more.
4.) E.g. PVS-14. I’ll probably go PVS-14 here.
5.) It occurs to me I haven’t picked a heavy rifle. It will be select fire (not that full auto with 7.62×51 mm rounds will be used much), and have some optic and a night vision laser. The optic might have more than 4x magnification. Basically something to fill a ‘modern Dragunov’ role.

Reports From The Range: Light Rifle Trials

When last we left Parvusimperator’s Rifle Works, we had a rifle built to a concept. Perhaps a somewhat vague and nebulous hodgepodge of a concept, but a concept nonetheless. So let’s get her to the range and talk Trials, see how she fared, and how we liked her.

But first, a name! Because the name seems to suit her, and for a bunch of personal reasons I won’t go into here, I’m going to call my light rifle Bridget. Say hello, Bridget.

Second, Bridget needs an optic. As built, she has no sights at all. So I needed an optic. I have a bunch of nice optics sitting around, but not one really suited to competition. Plus, I really like optics on my pistols. I usually carry one, and I almost always take a red dot equipped pistol with me to the range if I’m going to be shooting pistols. And a red dot puts me firmly into the Open1 division of any two- or three-gun competition. So, I shouldn’t really compromise on my optic in terms of close-in performance or performance at range. Which made my choice obvious: the SpecterDR 1.5x/6x.

Let’s look at this optic. It’s made by Elcan, a division of Raytheon. And it’s huge. It’s also unique in that it has a mechanically-operated prism system internally, giving it exactly two magnification levels. This is the bigger SpecterDR model, so those two levels are 1.5x and 6x. There is nothing in between, and switching between the magnifications is super fast. The conceit here is that for variable power optics, nearly all of the time is spent at either the lowest available or the highest available magnification. The SpecterDR gets rid of the others. It also features a massive 42mm objective lens, which is great for low light, or just getting a really clear sight picture. And if you’re a glass snob, the engineers at Elcan have you covered with some phenomenally clear European-grade glass. The reticle is a lot like a TA01 Acog: a big crosshair with bullet drop compensation markings for useful ranges. You can get a reticle calibrated for 5.56 or 7.62 as is your preference. Mine is calibrated for 5.56. The reticle also has a range estimator scale. You can illuminate either the center dot of the reticle or the entire reticle. If you’re illuminating the center dot only, you can get Aimpoint-grade brightness out of the Elcan. You won’t have an issue with that washing out. It’s rated for an average battery life of 3,000 hours, which is really good for a variable-power optic. Or, really, anything not made by Aimpoint. Plus, this thing is built like a brick shithouse. It’s not gonna break on me. It’s probably good for anything short of getting shot or having C4 strapped to it. It satisfies the MIL-STD-810F standards for durability, in case you like looking up technical descriptions.

Now for the downsides. Remember how this thing is built stupid tough? And it has a giant, Illuminati-approved, all-seeing objective lens? Well, it’s also a heavy beast of an optic, tipping the scales at 700 g (1.54 lbs.). This is a lot, but bear in mind that it includes a mount. So if you’re comparing it to a more conventional optic design, add in the weight of a mount and then get back to me. It’s a bit lighter than the super popular Vortex Razor HD Gen II 1-6x on it’s own, and rather lighter once you add a mount to the Vortex. Downside two is the price. MSRP is painful. And, downside number three is that Elcan is a division of Raytheon. They are a military contractor. This optic has an NSN. Having a super good warranty isn’t high on their features list. Nor is having a customer service department that can be there to hold your hand and reassure you that you are a special snowflake. They don’t care. If you object, feel free to take your business elsewhere. I don’t really care, so I ponied up the cash and bought one.2 Oh, the one other thing to be aware of is that the integral mount uses ARMS levers. Some people don’t like those because they’re not adjustable and don’t work if the rails on your upper aren’t in spec. There are better clamping designs now, but these work. Plus, I can’t change them out. Hardly a dealbreaker.

Enough of me babbling about the optic. Let’s mount it up! Even with the Elcan beast mounted on the rail, Bridget weights in at 7.53 lbs., which is lighter than Kat without her optic. It’s also about as much as Maryanne, my SCAR 16S, weighs without her optic.

Range trials proceeded without too much drama. That gas system runs great. No problems in rifle operation were found. Though, I didn’t run a ton of rounds through Bridget yet at this stage. In terms of handling though, I’m super impressed. Bridget isn’t front-heavy like most other ARs, and she’s not rear-heavy like a bullpup. The vast majority of the weight is concentrated right around the magwell, where your strong hand is. So she’s not tiring to hold up and maneuvers super easy. That long handguard is actually quite nice with the weight distributed this way. It makes transitions really easy.

What else did we notice? Bridget is loud. Very loud. And the blast is obnoxious. How obnoxious? Well, two lanes over, Fishbreath remarked “Holy cow that’s obnoxious!” And he’s not one given to profanity. Translating to something a bit more colloquial gives us “Fucking ow!” Fishbreath has also mentioned the sensation of getting blasted in the face with the particles that come out of the business end of a rifle is a lot like getting pepper sprayed.

That said, after understanding that Bridget is going to helpfully try to get you some extra shooting space so that you both can get comfortable, she’s a remarkably flat shooting gun. I’m no expert in recoil control, but that little M4-72 brake is amazing at keeping the muzzle where you pointed it. No jumping, no nonsense. Plus, even less recoil than you’d expect from a 5.56. Bridget feels like shooting a .22 that someone made heavy, but somehow is being magically supported. Oh, and you’re right behind a cannon that’s synchronized to you. Because roar.

In case it’s not obvious from the above, I like Bridget very much. She’s lots of fun to shoot. Having a light, well-balanced rifle is pretty awesome, and it’s a solid validation of my part selection. I’m quite happy with her as is. I was a little concerned that the heavy Elcan would ruin everything, but because of the balance, I don’t have any complaints. I might swap to something else in the future, but I’m happy with the Elcan for the time being. I’m also quite happy with my choice of stock and handguard. Thanks, BCM! I do need to remember a glove for sustained shooting, since the handguard heats up quick. The Geissele SSA-E is a good trigger, but I might like to try something different given my expected uses. We’ll see–I’ve got a match coming up on the 10th, and I’ll take note if any conclusions shake out of that match, other than I need more practice.

1.) Or “Un-Limit-ed” now, I guess. Name changes, ugh. Maybe I’ll call it Ultd. Anyway, same great nearly-no limits as Open, brand new name.
2.) I got mine from CS Tactical. They do have great customer service.

Parvusimperator’s Light Rifle

As per usual, I wanted to do another AR-15 build, which of course, needed a concept. I decided to try for a Light-ish rifle. I’m gonna pick some parts on the lighter side of things and see how I like the result. There are some exceptions, which I’ll get into below. Also, if possible, I wanted to give one of those long handguard things a try, see why everybody likes them. And I’m going to make this a nice, generally high-end race-ish build. So let’s cue the music.

Receivers: Mega Arms NiB-coated billet set
Well, that ended quick. Just kidding. Really though, I bought these because they look freaking cool. NiB (Nickel Boron) finish is pretty, and Mega Arms makes nice receivers. Billet receivers are heavier than forged, in general. Oh darn. Let’s look at the receivers themselves in detail:

Upper Receiver:
Well, it’s NiB coated, which looks cool. Internally, this should be pretty slick. Otherwise, it’s mostly adding a bit of bling that we can pretend is something vaguely resembling practical. This is a pretty typical billet upper, with some details particular to the manufacturer to make it look cool, and provision for a forward assist and dust cover.

Lower Receiver:
It’s also NiB coated. Plus, matched billet set, so the design is supposed to flow nicely. Blending and all that. Woo. There are a couple other things of note here that are nonstandard. First, there’s a small setscrew at the back to control fit of the upper and the lower and remove any wobble. Not that the wobble matters, but it’s nice to be able to take it out, get that custom gun feel. We also have an extra bit on the right side–a southpaw bolt release! There’s a button on the right and a longer guide rod so that a southpaw shooter can release the bolt easily with his support hand when he reloads. Cool. Note that there’s no way for him to lock the bolt back with this particular gubbin, but that’s okay. Bolt lockback is nearly always an administrative thing; it doesn’t matter if it’s awkward. Also, the bolt catch is to be held in place with an included setscrew, not a roll pin. Great! Roll pins are of the devil anyway, especially that one, which is about the most awkward thing to install.

Barrel: Daniel Defense 16″ Lightweight Profile CL
That’s more like it. It even says lightweight in the name. Anyway, I went with Daniel Defense because they have a good history of making quality AR barrels, 16″ because I don’t want to bother with pinning the muzzle device or NFA paperwork, and chrome lining (“CL”) because duh, chrome line that barrel for best barrel life results. The lightweight profile is what was originally called for by Stoner in the basic AR-15/M-16A1 design, so we’re in good stead here. Plus, I’m not a benchrest shooter, so I don’t want a barrel that weighs as much as a Camaro. Light rifle, lightweight barrel profile. Perfect for the Run ‘n’ gun.

Handguard: BCM KMR 13″
Oughta make up for all those places I opted not to cut weight. Note that this is not the KMR-Alpha. This is Original KMR, made with BCM’s fancy, proprietary, and apparently hard-to-find aluminum-magnesium alloy. Just like a fancy racing engine block. And it’s laughably light. Holding the handguard in your hand is like holding nothing at all. It’s stupid light. There’s basically nothing to it given that it’s over a foot long. Why 13″? Because I wanted to have a long handguard to see what all the fuss was about. But I still wanted a bit of barrel at the end for the narrow firing port drills you sometimes see at matches. This fits the bill for both. Plus, it’s got the modular keymod interface. Is keymod better than Mlok? I have no idea. I just like this handguard design. I figure both will be around for a long time, because people hang on to guns for a while.

Muzzle Device: Precision Armaments M4-72
I could probably have gotten a lighter muzzle device. I don’t care.1 The M4-72 is universally acclaimed as a super effective muzzle device, coming in at or near the top in several effectiveness tests. It is also apparently horrifically loud. I do not care about this either. Ridiculous race gun comps are always something I’ve been interested in trying. So here it is. One of the baddest of the bad, if you can take the abuse. Or, I guess if people around you can take the abuse.

Gas Block: BCM low profile .625″
Not much to say here. It’s a gas block. It attaches via setscrew, mostly because I lack a drill press to pin it properly. Oh well. .625″ because that’s the diameter of my barrel at the gas port. It is not adjustable, because I don’t really want to fiddle with gas systems too much. I don’t tweak rifles to shoot as light as possible for some custom load. I like my rifle to run with any reasonable factory load.

Gas tube: BCM midlength
Yes, I bought a gas tube. No, there’s nothing special about it. Makes rifle do that autoloader thing.

Bolt Carrier Group: WMD Guns NiB-X coated M16 BCG
Here’s another place where I could have saved some weight, but didn’t. Personally, I’m not a huge fan of low-mass components in the operating system, because I like unfussy, reliable rifles. This is one of the few places where there is mass in an AR-15, so of course someone is gonna try to cut weight here. If you go with a reduced-mass BCG, you nearly always need to tune your gas system for correct functioning. Since I’m not the biggest fan of fiddle-farting around with the gas system, and I have no capacity to do so on this rifle as designed, I kept the stock-dimensioned BCG for reliability. I don’t like fussy, high maintenance guns. NiB coated because my upper is NiB coated, and NiB on NiB is going to give me maximum lubricity. Plus, it looks really cool.

Buffer system: BCM milspec buffer tube, castle nut, receiver end plate, carbine buffer, carbine buffer spring
Not much interesting here. I need a buffer system to make the rifle one correctly. So I got one. It’s all pretty standard stuff. Milspec buffer tube, though it doesn’t really matter as long as it’s consistent with your stock. Castle nut and receiver end plate are also needed, and stock parts, and boring. Nothing fancy here. The buffer is carbine weight, mostly because that’s what came in the kit. I may tinker with that a bit, but Obsessive Buffer Tweaking Syndrome has screwed up many perfectly good guns. So…maybe not.

Stock BCM Gunfighter FDE
This stock is a good balance between weight, comfort, and durability. It’s one of the lighter stocks on the market, among the strongest in abuse/drop tests, and is pretty comfortable as far as cheek weld goes. There’s a rubber pad on it too, not that a 5.56 AR is abusive at all. There are lighter stocks, but most of them are less comfortable. Or I could have just gotten a backplate for the buffer, but that wouldn’t be adjustable. And I refuse to be that silly. Plus I like having features that were on the ban list for the ’94 “assault weapons” ban. Makes me feel warm and fuzzy. Oh, and I picked Flat Dark Earth (FDE to the cool kids, tan to everyone else) because it looks cool, and I’ve got a sort of two-tone look going on.

Various Upper and Lower Parts:
I’m going to list these out, grouped by function, because a bunch are decidedly not standard parts. I rolled my own lower parts kit for this one.

Forward assist: BCM forward assist and spring
Well, the upper receiver has a slot for one, so I got one. It’s a stock part. Moving on.

Dust Cover: Strike Industries Enhanced Ultimate Dust Cover
I got this because installing a dust cover is really annoying. This one is much less so.

Charging handle: Mega Arms Grip Charging Handle
This one came with my upper. It’s got some more grippiness, and it’s a billet part, but otherwise it’s a stock design. I’m fine with that for now. I haven’t had one of my guns jam up real bad, so I haven’t had to really abuse a charging handle. Maybe in the future I’ll get a fancy one.

Mag Release: Colt mag release spring, colt mag button, Norgon ambi mag catch
I got the Norgon ambi mag catch because I figured it’d be pretty silly to have an ambi bolt release but no ambi mag release. I got the Norgon one because it’s well made, puts the mag release in the same place for southpaws and even has an NSN. Other small parts are Colt because I like Colt stuff. They make good small parts.

Bolt release: Colt spring, Seekins Bolt Release Catch
These are added to the already-supplied extended guide rod to enable the southpaw-friendly release functionality. Colt spring because I still like Colt. Seekins catch because it’s a little bigger, and I like the look. Plus bigger is easier to smack when you’re in a hurry.

Safety: Battle Arms Development Ambi Safety
Again, ambi makes more sense as an all-or-nothing thing. Plus, I like ambi safeties in general, and I’m not sacrificing anything. Battle arms makes a really nice one that lets you choose from several different shapes of lever that they make. They come with a safety detent and safety detent spring.

Grip: TangoDown BG-17 FDE
FDE because two-tone. TangoDown BG-17 because it’s a really comfortable grip. It’s my favorite from testing several. And no, I don’t like the ‘more verticaler’ grips they have now. TangoDown’s grip is also shaped to keep your hand high, and a high grip is a better grip. Also, TangoDown actually makes grips in sizes for people who have big, manly hands. The BG-17 is the larger size, the BG-16 is the smaller size. Same great comfortable shape. Since I have relatively large hands, I went BG-17. Interestingly, all the goofy vertical grips seem to be made tiny. No idea why, but it’s another reason for me to not like them

Buffer retainer: Colt buffer retainer detent, Colt buffer retainer spring
Really, there’s nothing to see here. These parts are required so your gun works right. There’s nothing special about them. I like Colt, so I got ones made by Colt.

Receiver Pins: Battle Arms Development Enhanced Pin Set
These hold your receivers together. You need some pins, and the corresponding pin retaining detents and pin retaining springs. I like the Battle Arms set because they shape the pins a bit more to make them easier to push and pull with your fingers. It’s the little things. They also include a little magnet to hold the detents while you install the pins. It’s the little things.

Trigger: Geissele SSA-E
If you thought I was going to put a stock trigger in this gun, you should go play in traffic. I like Bill Geissele’s triggers, and his SSA is pretty much my go-to trigger. I went with the SSA-E for a little bit of match-ness. I might go with a more competition trigger once I get a feel for this one and run it. That trigger might be the Geissele SD-E trigger, or maybe the Hiperfire 24C that I’ve heard so much about. I’ll keep you posted.

There she is, though she still needs a name and an optic. And then it’s off to the range! Watch this space for more details.

Oh, and in case your curious, she weighs 5.975 lbs unloaded, with no optic. A hair under six pounds is pretty good, I thought. Especially because I didn’t get too obsessive.

1.) Technically, I could also have gone with no muzzle device. But that’s just silly. If you seriously considered this, then you’re dumb. Or too weight obsessed. Possibly both.

Kat’s new furniture: when a stock is not stock

Last time, I said I would open this post with my precise optics choice. Here’s why I tried to put it off: my optic is an Aim Sports 4×32 ACOGalike. (ACOGalike is not the brand name; that’s just my description.) A quick note on Chinese-built optics: if it doesn’t have Primary Arms on it, you can’t trust it. If you roll a 12 or greater on a d20, it’s probably worth using; if you roll a 20 and 12 or greater on a second roll, then you might have a hidden gem. I hit about an 18 on mine: it doesn’t show the same issues as some other Chinese optics in my possession, but it’s inferior to parvusimperator’s proper ACOG in terms of optical clarity and low-light performance. So it goes. I can buy ten cheapo Chinese optics for the price of his one ACOG; at least one of mine is going to be usable.

Anyway, same optical characteristics as a Real ACOG, which means limited eye relief. Originally, Kat had a polymer stock in the same vein as the stock AK stock, except lengthened a bit for parvusimperator’s monkey arms1. You can see the issue if you look at a picture of an AK stock: it slopes somewhat downward, and my cheek weld, for a relatively high-mounted scope with short eye, ends up being a beard weld, since you find yourself in front of the actual comb. This is not ideal.

The solution? A stock with a higher comb. There are varied and sundry options here. After looking at several options, I chose the Magpul Zhukov-S. “A Magpul?” you ask. “Fishbreath, aren’t you a massive cheapskate?” Yes, yes I am, but at the same time, I recognize quality when I see it. Let’s count the ways the Zhukov-S is a good choice.

Number one: the comb is straight back from the receiver. This fixes my chin weld issue: the comb is high enough that I can properly place my cheek against it, while being low enough that it doesn’t interfere with over-the-ear hearing protection.

Number two: it’s a side-folder. This is not of critical importance, but there’s something about folding stocks on AKs that just feels right.

Number three: the build quality is superb. The folding mechanism feels durable and has positive locking in the folded position; in the extended position, there is zero rattle. It may as well be a fixed stock.

Number four: the attachment mechanism. Magpul has solved probably the largest open problem in AK customization. This one requires some further explanation.

An AK stock is secured to the receiver by two screws: one through the tang poking out the back of the receiver, and one through an internal tang in the receiver a little bit further forward. These are not for precision alignment: they’re there for retention only. The stocks are precision-fit2 to wedge into the receiver, which prevents them from wiggling. This requires a good bit of force, and a good bit of fitting on initial installation.

Magpul decided this was a terrible idea. They came up with two innovations to make the whole process almost painless. The first is their so-called ‘wedge block’. Looking at the stock from the side, the forward bit which slides into the receiver is cut diagonally, longer at the top and shorter at the bottom. The wedge block is cut the opposite way; putting the wedge block against the forward bit of the stock makes a square. A bolt holds them together, and when you tighten the bolt, the wedge block slides downward. This pushes the stock upward, and eventually, the wedge block and the stock have wedged themselves against the receiver, securing themselves against it without having to be made the same size as the receiver.

The second innovation is a keyed nut: oval-shaped instead of circular, it fits into a cut beneath the tang screw hole in the stock. Magpul provides a machine screw to fit the nut, so when you tighten the machine screw, it ends up centered over the nut, which is positioned at a defined point in the stock, yielding correct side-to-side orientation. So, unlike most AK stocks, the Zhukov-S goes on painlessly. All you have to do is tighten a few screws to hold things in place; no mallet required, and the end result is just as solid.

Is it perfect? No, not quite. I’d love some storage, especially since my optic’s illumination is powered by watch batteries, not radioactivity or natural light, and as far as I can tell, my options are limited to duct taping things to the outside of the stock. Nor does it have the classic looks I usually go for: it’s a tacticool accessory through and through. Although it has sling swivel points, it doesn’t come with any of the push-button sling swivels they accept, and for the money, I feel like a swivel would have been a nice extra. Finally, it is a little bit on the expensive side; at about $100, it’s the most I’ve ever spent on a firearms accessory which is not an optic.

Don’t let those critiques take away from the product, though: it’s certainly worth the money.

1. This isn’t entirely fair. The stock is NATO length. I just don’t like ’em that long.
2. In AK Land, this means they’re cut a little large, and you bang ’em into place.