Monthly Archives: July 2016

OpenTafl v0.3.3.2b: the sun sets on v0.3.x

Releasing today is OpenTafl v0.3.3.2b, most likely the final version of OpenTafl in the v0.3.x series. How far we’ve come in the…1 month and a half since these releases kicked off2. After a few false starts, I’ve decided upon this set of features as the final, stable set for v0.3.x.

Beyond the obvious (network play and other associated features), OpenTafl has seen some incidental UI, AI, and framework improvements. Nothing major you haven’t already heard about, so I won’t go into too much depth here. You’ll find that the server login dialog is a little more informative now, and that network games no longer ask for a password when one is not required. You’ll also find (since my last post) that network clients can load saved games, large boards have some extra features (try the ‘info’ command!), network hosts can disallow replay or analysis, and that several network bugs have been fixed. Hit up the README for more information there.

From here out, excepting bugfixes to v0.3.3.2b, my work will be on two new branches. v0.4.x will likely be a long-lived series of releases, since it’ll have both a big-name feature (playable variations) and a long, iterative process of improvements (the AI). Stay tuned for news. I have a pretty good idea of how I want to do playable variations, and a post on that, going from design goals to implementation plans, should be coming soon.

1. Picture me consulting the README.
2. It’s even more dramatic when you consider that, as a public project, OpenTafl is now only about seven months old, and has grown at a rate of nearly 3,000 lines of code per month.

Parvusimperator & Eurosatory: A Look at Rheinmetall’s Lynx

Eurosatory 2016 has just happened1, and let’s take a look at some of the big ticket items. Specifically, let’s look at a new IFV from Rheinmetall.

I’ve written a lot about IFVs, and what’s clear is that there are a lot of different variations on the theme. Different armies want different things, and it seems nobody quite agrees with me (and my conceptual Borgundian army). Let’s see what Rheinmetall has to offer.

Unlike the Puma, the Lynx is a private venture aimed squarely at the export market. So they’ve had to keep costs under control, and develop for one of many armies. Or not–they’ve actually gone and made several different options that you can select from in the Lynx. The base chassis, under all the new stuff, is the same as the Marder 1 IFV. This is an older IFV design, but it’s functional. This saves on some testing, and allows a cost saving option if you can get your hand on some used Marders. The Marder is 1970s vintage tech, but it was a well-protected IFV in its day. And the Leopard 2 and M1 Abrams are both also 1970s vintage, and are still great choices with upgrades. Why shouldn’t the Marder 1 be?

That said, just about everything else is new. Engine, armor, sensors, weapons, suspension. And unlike the Marder, or any other IFV, there are options! We’ll look at what options are available, and then go over what we’d pick. Rheinmetall plans to expand this into an entire family of midsize armored fighting vehicles, but for now we just have the two IFV options.

First of the options is size and dismounts. The clever men of Rheinmetall have developed two versions of the Lynx: the KF31 and the KF41. The KF31 is 7.2 meters long, weighs 38 tonnes, and holds six dismounts. It has a 755 hp engine, so it should have no trouble keeping up with your MBT of choice. Here, you’ve basically got a Puma. Granted, it should be cheaper than a Puma, and it lacks the quick attach/detach armor kit, but otherwise it should meet the same combat profile and provide the same high-end sensor and protection levels as Puma. Cool.

The other size option is the bigger KF41. It’s 7.7 meters long2, weighs 44 tonnes, and holds eight dismounts. Eight! Be still my beating heart. Plus, they redid the suspension design to take the added weight on the KF41, and put in a 1,050 hp engine, so it should still be able to move well. Both the KF31 and the KF41 have blast-resistant seating for all nine or eleven occupants. Both versions, of course, have a crew of three.

Both also have similar turret options in the Lance turret, which is a COTS project. A Lance variant was used in the British Ajax AFV. The Lance turret is available in an unmanned configuration or a manned configuration, and both are available on either Lynx variant. If you want to have the commander be able to stick his head out of the turret, you can. If you want the crew isolated from the ammo, you can. The two man turret does have some reasonably effective ammo isolation, but the unmanned one is going to be better in that regard. You can also choose your gun: the Lance can be equipped with a 30 mm or 35 mm autocannon. Regardless of which size you choose, the Lance is designed to accommodate two ammunition types in a dual feed system, and has all of the electronics and shell-programming systems in place to handle airburst rounds if you so choose. The Lance turret also has the same great optical suite as the Puma, with modern thermal viewers for the commander and gunner, plus obligatory laser rangefinders. The commander’s sight is independent, of course, and is configured to be ready to synchronize to a remote weapons station. Just add RWS.

As a brief aside, while the Germans do not make such a gun, if you’re interested in the 40mm CTWS, that shouldn’t be too hard to fit to the Lance, since that’s what the British used in their Ajax.

But wait, there’s more. The Lance turret has a coaxial machine gun, in proper 7.62×51 mm caliber, unlike the Puma. Plus, it’s got an automatic barrel change mechanism with three barrels to keep up that sustained fire, since it’s not easily accessible in either the manned or unmanned turret versions. Further, the Lance turret can be fitted with a two-tube launcher for the Spike LR ATGM. Unlike the Puma though, where this has been claimed for a while but keeps getting delayed, this was mounted on the Eurosatory display model. You can have your ATGMs now with Lynx!

Protectionwise, Lynx is loaded up with the latest composites, and matches the levels of Puma at protection level C. It’s not easily removable though, so it doesn’t have that slightly better than normal strategic mobility of the Puma. OF course, that assumes that you not only have Pumas, but that you have a bunch of A400ms that work, and no one does yet. A stripped down Puma is still too fat for midsize airlifters that actually function like the C-130J.

The turret also has the usual smoke grenade launchers, plus plenty of cameras, just like Puma. No active protection system (hard kill or soft kill) is fitted though. You’d have to select one to add.

The display model at Eurosatory was the KF31, with a two-man turret, 35 mm gun, and ATGMs fitted. Built for the show, and looked great. Plus, got a lot of attention too. I know Rheinmetall will be entering the Lynx in the Land 400 competition, and I wish them the best of luck. No word yet on what they’re entering though, or what the Aussies have asked for.

What about Borgundy? Well, it should be obvious that yes, we’d totally buy this. I don’t have pricing information yet, but I might be able to scrounge something up or guesstimate. Anyway, we’d order the KF41 with an unmanned turret packing a 30mm gun and the ATGM launcher. 30mm because that should do whatever support job we ask of it and we get more rounds. ATGMs because duh. Eight dismounts because that’s a full squad, and unmanned turret for the extra survivability. We’ll just need to add the active protection system of our choice.

1. (I hope we aren’t giving the impression that we’re rich or famous enough to be there. Yet. -Ed.)
2. I’ve long thought that adding about half a meter or so of length to an existing six dismount design would give me eight dismount capacity, and would be a worthwhile improvement to the FV510 Warrrior or the M2 Bradley.

T-14 Armata fluid capacities

Kind of a short, oddball post here, but I thought it might be of use/interest to someone. Also, it’s probably easier for me to find it if it’s here. I stumbled upon a translated excerpt of the T-14’s manual, and here are the capacities for the fuel/oil/cooling systems:

Fuel System
Internal (under the armor) tanks: 860 L
External (outside armor): 755 L
Total nominal fuel capacity: 1,615 L

Like most Russian tanks, the Armata can mount a pair of 200 L drums on brackets aft. Therefore:
Fuel capacity with supplemental tanks: 2,015 L

Engine oil tank capacity: 80 L

Cooling system capacity: 125 L
(including heat exchangers)

Transmission hydraulic fluid capacity: 90 L

Gearbox hydraulic capacity: 20 L

Kit from the other half

Parvusimperator wrote some about his gear, so it’s only fair that I do, too.

Blackhawk! four-pocket chest rig
From everyone’s favorite cheapest decent brand, this chest rig has four large pockets and two small pockets. Each of the large pockets can hold a pair of rifle magazines of your choice, and the small pockets will hold a pistol magazine each.

The design is patterned off of the Chinese Type 81 rig, but isn’t quite identical. In keeping with the Chinese design, the pistol magazine pockets are placed one on each side of the four centered main pockets. All the pockets are secured by velcro. The large pockets are great: they fit the magazines well, and if properly velcroed, secure them to boot. The pistol pockets do what you’d expect: hold magazines. That said, the strong-side pocket is a bit of a pain to get the magazine out of. (See my next item for more on that.)

Anyway, Blackhawk!‘s product seems well-manufactured. They made it out of a properly heavy canvas-y material, which seems to me like it should hold up well under heavy use. (Since I’m only using it for the occasional two-gun match, ruggedness doesn’t matter all that much, but if it comes to a zombie apocalypse, I’m more or less comfortable with it.) At the price I got it for, I certainly can’t complain, especially since it claims it’ll work with AR-15 magazines, too.

Closing out my chest rig thoughts, I had nearly the same experience as parvusimperator: reloads played even less of a role in my time than they did in his. I found myself needing to reload my rifle exactly zero times while running a stage, not counting the stage in which the rifle started unloaded on a table. I could get by with a belt magazine carrier, but I see two obstacles to that: first, nobody makes belt AK mag carriers; second, I like using my ‘duty gear’, as it were, for competition. I’m very unlikely to ever need to use my handgun in a high-pressure non-sporting situation, let alone my rifle chest rig, but my thinking is the same in both cases. I have a limited time budget for practice, in the same way that I have a limited money budget for practice. Why would I spend either on a setup I’ll never use.1

My left front pocket
Rather than try to reload from the strong side pistol magazine pocket on the chest rig, I put my second spare mag into my pocket. The pocket was a little too low for complete comfort, but it’s spacious—I could have put a bunch more mags in, if I was trying to carry my full load from the start—and relatively easy to access regardless.

Would I bother with dedicated pistol mag carriers? On the one hand, I could definitely use a few. On the other hand, my current setup is perfectly acceptable, and I don’t know that I would use mag carriers enough outside of competition to merit the expense.

Unlike parvusimperator, I had to dip into my pistol reload stash on basically every stage. The difference between 15 (and my pistol marksmanship) and 18 (and his) is significant enough to tell. I might have liked having another extra magazine,

Company-issue duffel range bag
It isn’t a range bag by design—it’s just a small duffel with my company’s logo on the front—but a few airplane trips as my personal carry-on item really tore it up. After the shoulder strap fell off, I demoted it to ‘range bag’. Surprisingly, it handles range duty better, and hasn’t gotten any worse since it switched jobs. Would I like something with more padding, more space, and better internal separation? Yes, but this came in at just the right price2.

My glasses
Subpar eye protection, lacking in important qualities like scratch resistance. Ordinarily, your shooting eye protection doesn’t have to be scratch resistant, but I shoot with a wee, short-eye-relief ACOG-style 4x scope, so if my form isn’t perfect, the rifle whacks me in the glasses. My glasses don’t have quite enough anti-scratch strength to take that sort of abuse. I’ll probably get a set of over-glasses eyepro before my next go.

Howard Leight over-the-ear ear protection
I prefer earmuff-style earpro to in-ear things, for more attenuation and clearer indication to others whether your earpro is functioning or not. This one was inexpensive, relatively low-profile, padded over the head, and readily available at my local big-box sporting goods retailer. No complaints here.

1. Unless it’s interesting and historical, like the BritKit.
2. Namely, free.

Parvusimperator Reviews His Competition Kit

Or at least, reviews the stuff he took to the two gun match. Most of this isn’t really “for competition”, but you run the match with the gear you have, which may or may not be the gear you want. It’s better that way: now I know what changes I want to make. Had I gone out and bought a bunch of stuff right before the match, it would probably still be wrong. Anyway, let’s get on with it.

Rifle Mag Holder: Tactical Tailor MAV chest rig
I’m kinda split on this one. On the one hand, I really didn’t need it for the competition. I went to my rifle reload all of once, because 30 rounds is actually a lot, even when you’re double tapping. So I didn’t need a giant chest rig that can hold twelve AR mags. That said, it didn’t drop magazines everywhere. Retention is good. On the other hand, it’s a really nice chest rig. I got the “Two piece complete MAV” kit, which comes with four magazine pouches, each ready to hold three 30-round magazines. It also comes with two large utility pouches and two small utility pouches. So there’s plenty of space to haul things. The ‘Two piece’ part refers to the fact that this chest rig has a front closure, which is a lot easier to get on and off. The small utility pouches are sized for two pairs of handcuffs, or a similarly sized load. The large utility pouches are sized for a canteen, water bottle, 1.5 L hydration bladder or a properly-sized sandwich. The large utility pouches are closed with adjustable buckles; everything else is closed with velcro. I had no problems losing rifle mags from my chest rig.

The MAV is reasonably comfortable loaded up, but if I did that for long periods, I might want to replace the standard straps with the padded kind. The MAV itself is covered in PALS webbing, so you can place the pouches where you like (or swap them out for other pouches).

And yes, the MAV is Berry-amendment compliant.1 Great for a carbine class, a bit excessive for competition. I might get a belt holder for a single 30-round magazine instead, since that should suffice. Especially if I’m also loading up the Surefire Mag-60.2

Pistol Mag Holders: Blackhawk Glock Mag holder, PerSec Kydex Glock Mag holder
I used these because they were the pistol mag holders that I had. They go on your belt. They worked great. I didn’t lose pistol mags, unlike other people. I also didn’t need more than the two on my belt (plus the one in the gun). That said, the PerSec Holder is paddle-style, and while this is great for concealment, it’s less ideal for competition, because it’s rather wide and eats lots of belt space. I’ll want to move that to concealed-carry only, and get more things like the Blackhawk holder for competition.

Eye Protection: Smith Aegis Echo
I got these because I wanted something that met MIL-PRF-31013 and ANSI Z87.1 standards for durability, because I’d rather not lose an eye like Paul von Mauser. I picked the Echos in particular because they’re big, so they fit someone with a large head (me) well, and because they have thin alloy temples, so they work well when worn in conjunction with over-the-ear hearing protection. I usually like that (sometimes doubled up), so I figured this was a good choice. One small complaint is that if you’re not wearing the over-the-ear hearing protection that these are designed to work with, and you tilt your head down, to load a mag, say, these will slide down your nose. Oh well. When worn with muffs, they fit great and are super comfortable. I got these in a kit which came with a clear protective lens, a grey polarized protective lens, and a yellow protective lens. So, all the lenses you could possibly want for high light, low light, and indoor uses. You can swap lenses pretty easily in just a few seconds, and I have to give Smith Optics big props for making an easy-to-use, secure, quick-detach lens system.

Plus, they’re very comfortable when worn with muff-style hearing protection. Very easy to wear through the whole match, or a long class, without discomfort. Strongly recommended if you like over-the-ear hearing protection of any type, or doubling up.

Hearing Protection: MSA Sordin Supreme Pro-X
Yes, these are over-the-ear hearing protection. These are active, or “noise-cancelling” hearing protection. They’re stupidly durable, have excellent battery life, and are beloved by operators everywhere. The whole thing is waterproof. I got these with the upgraded gel earcups. These are absolutely phenomenal. Very wearable all day. When other people take their earpro off during periods when the range is cold, I usually leave these on. They’re that comfortable. Battery life is at least 600 hours of use. These have the regular headband instead of the neckband. That’s less good if you’re wearing them with, say, a helmet, but it is nice in that you can flip them around so that the microphones point backwards, making it easier for you to hear an instructor or range officer. I have absolutely no complaints with these. If you do want to double-up on your earpro, these are still a great choice for the outer component, because you can turn up the volume on non-cancelled noises to compensate for the earplugs.

There are probably those of you out there who are wondering why I would spend about $300 on NRR 18db hearing protection. My first answer is, would so many hardcore operator types wear them if they sucked so bad? In all seriousness, and because I generally dislike being lazy and just appealing to authority, hearing protection works differently against different frequencies. Since MSA is a responsible company, and does not know what frequencies you are going to want protection from when you buy their product, they list the low number. You will get 18 decibels or more hearing protection, depending on the frequency.

So what’s the relevant frequencies for guns, and what noise reduction do we get there? Well, for guns, you probably want to look at the 1-2 kHz range, and go as high as 4 kHz if you’re shooting a bunch of compensators. In that range, the Sordins are going to give you about a 30 decibel noise reduction. 30. Suck it, haters. Maybe that’s why people who have the budget and are hardcore love these things. Also, they’re super comfortable.

If you’re a super-scientific type, and want the really long version, check out this post from Trevor on the Trigger.

1.) I.e. Made in the USA from American-sourced materials.
2.) Just in case you hadn’t gathered, it holds sixty (60) rounds of 5.56 in a nifty quad-stack configuration.

Parvusimperator Reviews the LMT MARS-L

It’s no secret that I’m not a fan of bullpups. I don’t think that shorter overall length is worth all of the other compromises you get with bullpups, like awkward reloading and godawful triggers and no place to put accessories. I am also a huge fan of the AR-15 platform, so when the New Zealand Defence Force picked a direct-impingement AR-15 in the LMT MARS-L to replace their Steyr Augs, I was thrilled. Ecstatic even. This is also a victory for direct impingement over op-rod systems. It was a very good day. Let’s take a closer look at the MARS and see what improvements LMT has made.

The MARS-L is an offshoot of the CQB16. The biggest changes to the stock CQB16 are in the lower, which is now totally ambidextrous. Ambi safeties are easy to do, you just add a lever on the right side. With a little bit of work with a lever and cam, you can get an ambi mag release without too much trouble. The ambi bolt release requires a bit of extra work to the receiver, and there are a handful of companies out there who will make one for you, including LMT, Knight’s Armament, and Mega Arms.1 The changes are relatively minor, and while they add a couple machining steps and small parts to complete final assembly of the lower, it doesn’t substantively change any of the interfacing parts, so you can add any old upper to the ‘ambified’ lower.

In terms of the rest of the lower, it’s pretty simple. It uses LMT’s SOPMOD-pattern stock, which is an excellent choice. Most pictures I’ve seen also come with an ‘ergo grip’ which is a much better choice than the lame A2-pattern pistol grip. I’m not sure if that’s what’s being delivered to New Zealand though, or if that’s just on the display models because that’s what LMT usually uses on the rifles they build for guys like me. The trigger group is safe/semi/full auto.

The upper has a few differences from a regular M4. The most obvious is LMT’s monolithic upper. The picatinny quadrail handguard and upper receiver are one piece of aluminum, which is clearly stronger than having two separate pieces. It also looks cool, and means you never have to worry about sights getting jacked up because your handguard got knocked around or sucks. The barrel is held in place by a pair of torx screws, which makes barrel changes easy. Not that this is a big deal for most troops, but it’s still pretty cool. It does lock you in a lot more to picatinny rail interfaces on your accessories, but that’s not a bad thing. That interface isn’t going anywhere for a while–it’s got a ton of momentum and lock-in from being around for a while. A lot like the 5.56 round. Note that the regular grunts get a CQB-length (9″) handguard, and the special forces guys get a longer (12″) one. The regular grunt version has a bayonet lug mounted on the right side of the barrel. This way, it doesn’t get in the way of a grenade launcher mounted under the barrel on the quadrail.

While in the civilian world, Picatinny rails aren’t the most popular thing, and quadrails are decidedly old-school, for the military they’re still the right choice. They have lots of picatinny-rail accessories in the system already. Many of these do not have Mlok or Keymod versions, so adapters would be required. Which gets you back a bunch of weight that you got rid of by going to Mlok/Keymod. Plus, you can’t get rid of picatinny rails entirely, because optics mount to *those*. Mlok and Keymod aren’t designed to let optics retain zero after mounting/dismounting. And you can’t get a receiver with those. Plus, you can get a 40 mm grenade launcher to attach to quadrails. No such luck for Keymod or Mlok. So why bother with a bunch of redundant attachment methods. Suck up a bit of weight, and stick to quadrails, if you’re an army.

Internally, it’s got the LMT improved bolt. The Special Ops one has the LMT improved bolt carrier. I’ve already talked about these2, so I’ll just summarize and say that they are redesigned a bit to improve the life of these small parts. I like the design. Anyway, you might be wondering why not an op-rod AR design? There are a lot of those out there, and lots of people seem to like them. And that’s basically what the HK 416 is. But it doesn’t really get you anything, and it has its own downsides. Most of the HK 416’s ability to take sustained fire longer is due to the heavy barrel profile. Colt can get you almost the same thing for less trouble on your AR-15 with the SOCOM-pattern barrel used on the M4A1. More barrel, more fire. And LMT does not use lightweight barrels on their builds.

The op-rod is a conversion, and it adds issues in that you’re applying forces in ways the bolt carrier wasn’t designed to take, so it can tilt and have issues with wear. Also, the op-rod adds weight. The direct impingement system puts the ‘piston’ bit inside the bolt carrier, so there’s no op-rod to deal with. Which means no op-rod weight. Even if you’re concerned about the gas tube melting, you can beef that up a bit and still come out way ahead in the weight department. Adding an op-rod to an AR is a solution in search of a problem. Not that op-rods are bad, just design the gun from the ground up around the operating system. Like you should. Or just crib from the AR-18 design like everyone else.

But enough about technical gun engineering discussions. What does this give the Kiwis that they don’t have with their AUGs. Well, it’s replacing the Aug A1, which had a fixed 1.5x optic. This was revolutionary in the 70s when the Aug was introduced, but it’s eclipsed now by much more capable optics. The MARS can accommodate the fancy optics of today and tomorrow with it’s rail interface for adding sights. It also can mount (and comes standard with) folding backup iron sights, which is piece of mind.

Further, the conventional layout means that in recent urban warfare engagements, you can switch shoulders to take opposite corners at will without eating brass. Plus, you get a better trigger, and although we’re not talking match triggers here, godawful triggers make for politically embarrassing hits on bystanders. Just look at the NYPD’s 12 lbs pull weight triggers on their Glocks.

One more thing comes to mind, and this one isn’t thought of a lot, probably because most people don’t shoot very much. If your gun hasn’t malfunctioned, you haven’t shot it enough. Fact. And, because of where the bullpup action is, and how sealed up it has to be to keep your face safe, when a bullpup malfunctions, clearing it is a massive pain. Tearing a weapon apart on the range sucks because you’re always losing things. Have fun doing it under fire.

It’s nice to have a real-world military agree with you. Go Kiwis! Say, the MARS-L looks an awful lot like the rifle I specced out for issue.

This is the best 5.56 service carbine around, bar none. Better than the SCAR, better than the G-36, better than a regular M4, better than any lame-ass bullpup, even better than the 416. Better than the XM-8 if that was still a thing. Sorry HK. We’d take them in a heartbeat. Specifically, the regular infantry version, with the bayonet lug and shorter handguard, but we’d specify that enhanced carrier.

1.) Check out my build notes here.
2.) See my Milspec Challenge article

Resurrected Weapons: XM-8

And now time to examine another futuristic weapon, the XM-8. This was an offshoot of the failed XM-29 project, where some in the US Army tried to get a more direct replacement for the M-16.

The XM-8 was a carbine firing 5.56 mm rounds. No fancy caseless ammo, no airburst grenades, just bullets. The same bullets that cranky guy up the street shot in Vietnam, even. What was different here?

The XM-8 was designed to be lighter and more reliable than the M-16. Reliability would be improved in a number of ways. HK built the XM-8 around it’s highly successful short-stroke gas piston system that had been used in their G-36. The body of the weapon was entirely polymer, with easily swappable components, and design by the Udelhoven Design Studio.1 Plus, while there were a number of ergonomic and internal design improvements over the stock G-36, they used the G-36 magazine.

Let’s talk feed devices. Recall that the original AR-15/M-16 magazine was a 20 round box magazine with no curvature. The magwell was designed to accommodate this, and is also not curved. Army desires for a 30 round magazine required some amount of curvature to accommodate the taper of the 5.56mm cartridge. But the magazine had to be compatible with all M-16s, so the top had to be kept straight. So there’s a kink in the 30 round magazine where the curved section meets the non-curved section, and this can cause problems. The G-36 magazine has a continuous taper, and is made of translucent polymer, so you can see how many rounds are left.

The G-36 is pretty “European” with a paddle magazine release, and most bolt work being done with the charging handle, which is atop the gun under the raised sight rail. It can fold to either side for ambidextrous use, and can be locked to either side for use as a forward assist. The XM-8 made some improvements here too. A shoe, sort of like what’s on an HK pistol, was added to the mag release so you could press a lever on either side of the trigger guard with your trigger finger to release the mag. Bolt release was in the front of the trigger guard. The selector was the usual ambidextrous affair, with safe/semi/full auto on the trigger group.

The XM-8 also tried to improve accessory attachment methods. Picatinny rails are expensive to machine, and add weight to the weapon and height to the accessory mount. For the same reasons that we would see the development of Keymod and Mlok in the civilian world in 2014, HK and Picatinny came up with PCAP. Just like Keymod and Mlok, PCAP uses a bunch of negative attachment points2, but it was designed to totally replace Picatinny rails. Specifically, it was designed to be a superior sight attachment system. PCAP naturally mounts things in the same place each time, so sights naturally will hold zero when mounted and dismounted.

Further, the XM-8 had a new sight. The XM-8 had to be lighter than an M-16, so a sighting unit was designed to integrate a red dot sight and an infrared laser sight. This gives day/night capability in a single unit, with one battery, that’s lighter than the two separate units with two batteries and two sets of mounting hardware. Plus, the sight was synchronized so that sight adjustments to the red dot also adjusted the infrared laser sight. The military version was called the ISM-IR. If you’d like one with a visible laser sight, the civilian version is so equipped, and is the ISM-V.

Of course, then politics intervened. No army requirement was actually listed, so Congress started asking questions. HK’s competitors started asking why they hadn’t been given a shot to deliver something new if the army wanted that. Plus, some people had spent money earmarked for OICW on the XM-8, and that brought up more questions. In the end, the XM-8 was cancelled for being too expensive for what it was. At the end of the day, it was more reliable, but still fired 5.56 rounds downrange.

So what do we think? If you’re looking for a new carbine system, because you’re finally joining the 5.56 train or your previous issue carbine is old and busted and you want some new hotness, the XM-8 makes a good choice. Though, it does require new accessories because of the new attachment system.

Honestly, that might be one of the better parts of the XM-8. We really like PCAP, and we especially like the ISM-IR. That can be had in Picatinny railed form too if you want. Plus, at some point, you have to accept some development costs to get something better in the system. We’re seeing some forces go to Mlok3, and PCAP is better because it gives you a sight solution too. On the other hand, we’d really like to compare it to some of the more refined AR-15s and similar that have come out since the XM-8 program was cancelled.

Verdict: Funding Approved for program testing by the Borgundy War Department Ordnance Procurement Board

1.) They also do design work for Audi.
2.) Also known as holes. Precisely cut and aligned holes.
3.) Including Canada.

Resurrected Weapons: XM-29

The saga of attempting to improve the effectiveness of the average infantryman continues today. Now it’s the turn of the Americans. In the late 1990s, the US Military wanted to try to replace the M-16. Again. And the conclusion of the experts was that bullet-launching technology had peaked with the M-16, and there weren’t any good ways to improve it further. So more lethality would have to come elsewhere.

Considering the problem of an enemy behind cover, the committee decided that the right answer was to have some kind of man-portable airburst munition. And this led to the design of the XM-29 OICW.1

The XM-29 had three components. The critical one was the grenade launcher. It was a bullpup-looking affair, firing 20mm grenades from a six-round detachable box magazine. These were quite a bit smaller than everyone’s favorite 40 mm grenades, so as to be workable in a magazine, but there still weren’t many of them. Which led to the second component–the “KE Module”, which was a 5.56 carbine made by HK. It had a conventional configuration, and only an 8″ barrel. Further complicating things, the one trigger on the carbine had to also work the grenade launcher, but you had to be able to separate the two modules and use them individually (after a trigger unit was added to the grenade launcher. Plus, there was a massive thermal sight/laser rangefinder/fire control computer unit on top to coordinate the airburst over the head of the enemy. The idea was that the operator would use the rangefinder to determine range, manually program in the distance for airburst, and then fire a grenade.

Unsurprisingly, the result was big, heavy, and very expensive. Fully loaded, the XM29 weighed 8.2 kg, or a hair over 18 pounds. That’s ridiculous. It was big and unwieldy. Oh, and did I mention the cost? The XM-29 was projected to costvover $10,000 per unit. Plus, airburst grenades are roughly ten times as expensive as regular, contact-fused grenades.

All this might be forgiven if it worked. It didn’t. Oh, the carbine bit fired ok. But there were tons of problems with the airburst mechanism. And when it worked, it was judged insufficiently lethal. The 20mm round created fragments that were too small, there was insufficient explosive for a very large kill radius, and a whole bunch of fragments and energy are going to be directed upwards, away from the target. I can’t imagine that it would have been all that combat effective to have to manually program in airburst distances when enemies were firing back either.

After dumping a whole bunch of money into the airburst 20mm rounds, it was finally decided that they were unworkable. The only way to get sufficient lethality was to up the caliber. 25mm was settled on, but this would mean an even bigger grenade launcher unit. Between the ballooning weight and rapidly escalating cost, the project was terminated, and split into the XM-25 (which I’ve talked about here) and the XM-8 carbine (which I’ll talk about later).

So that’s the overview. What do we think of this project? Well, the basic concept might be sound, since I’m all in favor of raining death upon my enemies, but the execution is terrible. It would be much better if the grenade module could attach to an existing rifle to reduce costs, like the Korean K11 program. This also uses a 20 mm grenade module though, and I share the US Army’s concerns about inadequate killing capability of the 20 mm grenades.2 The 25 mm grenades of the XM-25 are more effective, and a 25 mm launcher is far too big to mount on a rifle.

An even better solution would be to get airburst 40 mm grenades. There, the launchers and the grenades are already in the system. Lethality has already been proven, and there’s already cheap grenades in the system. You simply have to work out the guidance and fusing, but you’d have to do that anyway with an XM29-type weapon.

Verdict: Funding Denied by Borgundy War Department Ordnance Procurement Board

1.) Objective Individual Combat Weapon. They chose the stupidest name they could.
2.) I have no idea if the South Koreans are satisfied with the performance of the 20 mm, or if they’re banking on the enemy being unarmored, malnourished North Koreans who are also easily frightened or something.

The Crossbox Podcast: Episode 9 – Shooting the Breeze

This month, radio gremlins do not replace our show with something straight from 1940, we talk about artillery through the ages in more ways than one, and we report on hitting the dusty competition circuit.

Further reading
Japanese license-built Krupp 12cm howitzer
7.7cm Krupp field howitzer, pre-hydraulic recoil, used by the Boers in the Second Boer War, still superior to British artillery in South Africa
Artillery causes 80% casualties in the Donbas war
Three Kat articles
Intro to Glockblaster

Continue reading

Resurrected Weapons: The HK G-11

We’re going to look at some prototype rifles that never got off the ground. First is the most exotic, the HK G11.

Back in the 80s, the Bundeswehr issued the G3. They hadn’t yet gone over to 5.56mm yet. And they noticed the classic problem of soldier marksmanship: Most soldiers are very poor shots in combat. But what to do about this problem? Automatic fire is hard to control. It can be done with sufficient training, but we’re talking about the average grunt here. A burst of three or so rounds might sound like the ticket, but subsequent shots tend to miss high and right (or left) based on body mechanics and how they interact with recoil. Consistent high right missing isn’t super helpful for getting a higher hit percentage out of a weapon. What if the burst was out of the gun before the recoil impulse got to the shooter? Three superquick rounds. That might give you the spread you’re looking for.

A brief side note: the US Army, with their cool guy M16s noticed a similar problem, and would launch a search for a similar solution, the Advanced Combat Rifle program, based on similar reasoning to the above.

So we want a burst mode that’s super quick. 2,100-rounds-per-minute quick. That’s gonna be tough. And we’re going to want regular rates of automatic fire if we set the selector to full auto. Here comes the complexity. The engineers at HK considered the problem, and decided on an enabling technology: caseless ammo.

Without that pesky case, there’s no extract/eject portion of a normal operating cycle. Less to do means it’s easier to do it all quickly. Yay! Plus, caseless ammo is way lighter than cased ammo. A gain for the logistics geeks. Plus, this would be a SCHV round: 4.73×33 mm1. This worked to to being significantly lighter than M855 5.56. Rough back of the envelope calculations shows that for about the same weight as a G-3 and 100 rounds of 7.62×51 mm, a soldier could carry a G-11 and 500 rounds of ammunition.

Now let’s get back to America. To get adoption, the US Army wanted the ACR rifle to have a 100% higher hit probability than an M16A2. The G-11 was one of the entrants. Plus it had to be durable and reliable, etc.

A few other notes on the G-11, the rifle to fire these tiny caseless rounds. It weighed about 3.6 kg empty, had a Hensholdt unmagnified reflex sight, and a 45 round box magazine. The G-11 had integrated storage for two additional magazines for quicker reloading, sort of like the redi-mag system. It also had a bottom ejection port for ejection of misfires, or administrative clearing. You might imagine the mechanism to handle the 2,100 round per minute hyperburst plus regular full auto would be complicated and it was. And caseless made it worse. But it worked.

For the hyperburst, the barrel, firing chamber, and magazine assembly were all free floated and recoiled together. Picture a modern howitzer, except much smaller. And the nature of the mechanism meant that you’d get the three projectiles out before that recoiling assembly hit the back of the receiver, which is how they avoided transmitting the recoil for a little while.

Reloading was an interesting design too. Cartridges were in a box magazine above the rotating chamber, and were dropped in tail-first and then rotated 90 degrees into firing position. Turning a cocking lever further would dump a cartridge out the bottom if needed.

Now, let’s talk about the problems. You see, the cartridge case, that pesky bit that we deleted to cut weight and simplify the firing cycle, actually gives us a lot. For one, the cartridge case makes it easy to unload the gun. You can pull pretty easily on the rim of a cartridge case. You can’t pull easily on a compressed powder block. And you’ll want to unload it if a round fails to discharge and you need to get rid of it, or if you’re just done at the range and putting your weapon back.

The cartridge also protects all of your propellant. A cartridge case is relatively durable, and is insensitive to scratches and nicks that might arise from rough handling. It is also reasonably water resistant. No such luck for the caseless round. There were problems with damaged cases and extraction was a pain.

Further, the mechanism got weird because there’s no case to provide a seal at the back of the chamber where the firing pin is, or to seal off the barrel behind the fired bullet. Enter more complexity and a little plastic bit that went at the end of the caseless round to seal the barrel. Barrel sealing problems persisted, though.

Less obviously, the cartridge also provides a great way of getting rid of heat. A bunch of heat from firing the gun goes into heating the cartridge, not the chamber, and then the hot spent cartridge is ejected. Goodbye heat! HK had to contract with Dynamit Nobel for some special insensitive propellant that was then lacquered and used that for the rounds.

Lots of engineering and testing got these problems sorted, more or less. And here’s where the story gets vague. Depending on who you ask, there may or may not have been some thing that weren’t quite sorted. But they were sorted to the satisfaction of the Bundeswehr, who was about to adopt the G-11 in 1990, and there are plenty of documents to back that up. But then the cold war ended. Goodbye Soviet Union, goodbye scary threat, hello expensive reunification. And here the Germans decided against the G-11, which would be massively expensive. Remember, you’d have to set up new weapon and ammo production lines, and the ammo production lines would be entirely new methods. It’s not just a different size of brass/steel cased bullets. NATO wasn’t about to retool with the Soviet Union gone. So instead the Germans moved to (finally) adopt 5.56.

As for the ACR project, well, that was really more of an investigation than a serious replacement effort. And even though soldiers liked the compactness,2 reliability, and capability of the G-11, and even though the G-11 exhibited a significantly higher hit probability than the M-16 (or the G-3 for that matter), it did not meet the 100% higher hit probability, and was not adopted.

Where does that leave us, then? Well, it’s time to decide how we rule on this. And the G-11 has an advantage over some of the other weapons we’ll look at in that it’s doing some things that an M-16/SCAR/whatever-5.56-carbine-you-issue-now can’t do. Namely, that fancy hyperburst, and way more ammo for the weight. Plus, since the ammo in question is square, it packs more compactly too. So there’s a logistics win and a weight of fire win. Both of which I really like. Some of the G-11K2 prototypes even were fitted with picatinny rails to mount different optics, so I don’t even have to worry about having that done.

That said, there are some concerns we’d like to put to rest. Since it’s been a while, let’s get a few LRIP guns to make sure the manufacturing process is still good, and do some high round count testing. Plus, I’d like to do some gel tests and intermediate barrier3 tests. Even if that means some projectile design updates to make the terminal effects satisfactory, I can’t forsee any major problems left.

Verdict: Approved for LRIP and phased adoption by the Borgundy War Department Ordnance Procurement Board

1.) Or thereabouts. I’ve seen some variation betwen 4.7-4.9 mm or so.
2.) Despite looking like a space 2×4, troops even liked the ergonomics
3.) Usually sheet metal and tempered glass, i.e. car parts.