Author Archives: parvusimperator

USASOC’s URG-I for the M4

Thanks to SHOT Show and the good folks at Brownells, we can see what the US Army’s Special Operations Command is doing to improve their M4s. Let’s take a look. First, the product page.

Now, there are a bunch of things to note here. The upper receiver is unchanged. Still has that forward assist and that dust cover. The 14.5″ barrel is made by Daniel Defense, who have some excellent cold hammer forges for such things. The barrel has some unspecified improvements to work better with M855A1 ammunition, which has an exposed, hardened steel tip. I would expect these changes to be to the geometry of the feed ramp in the barrel extension, but I can’t confirm this yet. And I don’t know if there are other changes. The rest of the barrel is pretty boring. 1:7 twist rate, that government profile1, and a midlength gas system. The midlength gas system is a noticeable difference, being somewhat longer than the standard carbine length. A midlength gas system is somewhat softer recoiling, and probably leads to improved reliability when using a suppressor (which increases the gas pressure in the system). Note that they did not specify the medium-weight “Socom” profile barrel. Overkill for expected uses? Not proven? Weight Conscious? I’m honestly not sure.

The handguard is Geissele’s Mk 16, and is 13″ long and free floated. It has a picatinny rail at the top and Mlok slots all around2. This is a big improvement over the usual plastic handguard or the KAC RAS system, which has picatinny rails and isn’t free floated. Plus a longer rail means more room for one’s hand as well as accessories. The older handguards had room for lights and lasers or your hand, but not both. Geissele handguards are very nice, and have a well-designed attachment system.

The full length handguard means the standard triangular front sight block has to go. It’s been replaced by the Geissele Super Gas Block, which is low profile, and held in place by two setscrews and a taper pin. I like pinned gasblocks. They’re sturdier. Good choice here.

Geissele also makes the charging handle. It’s bigger, sturdier, and better suited to just grabbing or pulling at one side, like lots of modern guys do. It’s a fine choice.

The other difference in play is the muzzle device. The Brownells version (for civvies) has the Surefire S3F, which is a three-pronged flash hider that also serves as an adapter for the quick-detach mechanism used in Surefire’s silencers. The military is probably getting the S4F (with four prongs). I don’t know why the difference there. It’s still a suppressor adapter, and remember, Surefire’s silencers won the SOCOM testing.

Overall, I’d say it’s a pretty solid set of improvements, and results in a gun better than the previous PIP. I would like to see more if it were up to me, namely a better barrel profile and some bolt carrier group improvements. Both Lewis Machine and Tool and Knights Armament have some available improvements there, and I’d like to see some evaluations. Especially if suppressors are going to be used a lot.

Will I buy one? No. I don’t have much use for factory uppers these days. Building my own isn’t hard, and then I get to make all of the parts choices, and get things suited for me and my uses. And I don’t do clone builds. But it’s a solid upper if you’re in the market for one.

Finally, let’s do a quick weight comparison with the upper for a standard M4. The lower is separate, and needs no changing provided it has the safe/semi-/full-auto trigger group. Some of these weights are approximate because of what is and isn’t available on the market yet, but I wouldn’t expect them to change too much. I’ll update these as I get better numbers.

PartM4Weight (lbs)URG-IWeight (lbs)
Barrel14.5″ gov’t.1.614.5 gov’t.1.6
Upper receiverA30.6A30.6
Handguarddouble shield0.72Geissele Mk 14 (13″)0.75
Gas BlockFSB0.33Geissele sgb0.1
Gas Tubecarbine0.04midlength0.05
BCGstandard0.72standard0.72
muzzle deviceA2 Birdcage0.14SF3P0.24
charging handlestandard0.08geissele sch0.09
TOTALM44.23URG-I4.15

Notes: Upper receiver weight includes the dust cover and forward assist. Listed handguard weights include all mounting hardware. The Mk. 14 only has Mlok slots at 3:00, 6:00, and 9:00.

Not bad. Despite the stupid government profile barrel, a little weight was trimmed.


  1. Which I hate. A lot. It’s profoundly stupid, but that’s probably why it’s called the “government” profile. I guess we can’t expect them to fix everything at once. 
  2. “All around” being 1:30, 3:00, 4:30, 6:00, 7:30, 9:00, and 10:30. Also, Mlok is lighter than picatinny rails, woo. And some study found it tougher than the rival keymod. 

Parvusimperator Reviews the PX4C

Okay, this is Fishbreath’s gun, it’s true. And I’ve been pestering him to review it, but he hasn’t.

Fine. I’ll review it.

Don’t worry, Fishbreath. I’ll do my best to be impartial.

The PX4C (Compact) is a newish double action pistol from Beretta. Well, certainly newer than the Beretta 92, which is what you probably think of when I say “Beretta handgun”. The PX4C doesn’t have a ton of market share, partially because Beretta is bad at marketing, partially because Beretta hasn’t kept market share amongst law enforcement departments (see: Is Bad At Marketing), and partially because the PX4s came out a bit too late. The PX4s were released in 2004, when double-action triggers were going out of vogue. And there they have more or less stayed. If they came out in the 90s, back when double action triggers were Still Cool, they would have sold like crack, and you would hear lots about how nice they were.

Which brings us to an obvious point. These are double action semiautomatics. I am not a fan of these, personally. If you are not either for whatever reason, then (1) these will probably not make a convert out of you and (2) these can’t be turned into something that they aren’t: a striker-fired or single action only pistol. If you want something else, get something else.

On the other hand, if you are a fan of double action pistols, then the PX4C is a great choice, because it is about Glock 19 sized and polymer framed. The Glock 19 size (roughly) is big enough that you can easily get a good grip on the gun, but small enough that most people won’t have too much trouble concealing it with a modicum of effort. You can get good shooting smaller pistols, and you can conceal bigger pistols with a little more effort, but the Glock 19 is the sweet spot of balancing concealability and firepower. This gives you the same size package, the same fifteen round capacity, but a double action trigger. It’s also the only game in town if you like the double action trigger and want something in the Glock 19 form factor (and don’t feel like giving up a couple rounds). That’s really cool.

Oh, and polymer framed because it’s nicer to carry less weight around on your belt.

The PX4C has the Beretta-standard safety/decocker on the slide. I’m not a fan of this location, but it’s easier to reach with your strong hand than on a Beretta 92. You can convert it to a decocker-only lever with a really easy parts swap, and these parts are easy to come by.

I’ve also heard some occasional stories of issues if these pistols get dry, like in high round count classes. To the best of my knowledge, this hasn’t happened to Fishbreath, but he doesn’t do 2,000 round marathons of shooting. The PX4C might be a little needier of lubrication than, say, a Glock. I don’t know enough about this to know how big an issue it is. The occasional story comes up. I can’t confirm the cause either. The rotating barrel system is different, for better and for worse. It does make the pistol a bit softer shooting, but 9 mm isn’t all that stout to begin with. It might be more interesting to try one in .40, but I don’t have access to one.

The PX4C comes with interchangeable backstraps, which is nice. They could be grippier, but I say that about everything. This is easy to fix with some stippling or skateboard tape. Or maybe you like a smoother grip, in which case the PX4C is perfect for you as-is.

There’s actually a decent amount of Beretta parts support for these. There are low-profile safety/decocker levers, low profile slide releases, and a variety of sizes of mag catches. You can also use the mainspring from a Beretta 8000D to improve the double-action trigger pull by a significant amount. And, unfortunately, there is where the support stops. With searching you can find holsters. It is very difficult to find sight alternatives, though Trijicon does make both their standard three-dot tritium sights and their HDs for the PX4s. Stock sights are three-dot units.

So there you have it, readers. The PX4C is a great option for you if you like to carry reasonably-sized double action pistols. In which case, you owe it to yourself to give these a go. They’re pretty easy to overlook given all of the fancy Beretta 92 variants of late, but these are quite a bit easier to carry.

Also, if you’re on the fence, there’s an Ernest Langdon Custom Carry Edition, with actually good sights and all of the low profile controls added right out of the box. It also even comes with some grip tape. This is the version I would suggest you get, dear reader.

On Glock Safeties

A few weeks ago, Fishbreath and I were looking at another striker-fired pistol1 being found to be not drop safe. Fishbreath commented that he’d really like to see these barrel-up-at-30-degrees drop tests done to the Glock 43 and the M&P Shield. I promptly obliged him with a video. Glocks have three safeties designed to work together to prevent firing when dropped at any angle. Let’s take a look at how they work. An understanding of the trigger mechanism and the safeties it employs is also useful when attempting to modify that trigger system.
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SIG P365

The market for small single stack (and staggered-single stack) pistols for concealed carry is huge. In my eyes, they’ve neatly usurped the old S&W J-Frame in the small concealment weapon space. Perfect for NPEs and the backup gun role. For my money, I’d much prefer striker fired triggers to heavy double action revolver triggers. Plus, the sights on the Glock 43 and M&P Shield are easily interchanged. Sights on most J-Frames aren’t. And what comes on the gun are atrocious.

So it makes sense that SIG would try to get in on this market. Using the same sort of striker-fired action as in their P320, they’ve come out with the P365. It’s sized in between the Glock 43 and the M&P Shield, as seen below

Glock 43, P365, M&P Shield
From left to right: Glock 43, P365, M&P Shield.

What makes the P365 special is the capacity. Where the Glock 43 holds six rounds with the standard, nonextended basepad, and the Shield holds seven rounds with the standard, nonextended basepad, the P365 holds ten rounds with the standard, nonextended basepad. It’s still thin and small, so it will still conceal very well. But more bullets. More bullets is better. Otherwise, ergos are very much a slimmed down P320. I’d expect the trigger to be like the P320 as well, so short and heavy and doing its best to resemble the single action trigger of something like a P226 or P229. Eminently shootable to be sure, and way better than the trigger on a J-Frame.

This idea sounds like a winner. And it probably will be. I have my reservations, at least as of when this goes to press. First, I don’t like to buy first generation anything for firearms. I am not a beta tester. I am not a member of anyone’s QC department. And I don’t do that work for free. So I’ll wait a little, just to make sure the bugs are gone. And that goes double for anything that says SIG on the side. Between the P320 drop-safety recall and their history of QC problems with their traditional P22X guns since setting up the plant in Exeter, they get an even longer wait. I do not like the current management either.

All that said, I would like this gun to work well, because I’d love a small backup gun with more bullets.

On the Glock 19X

Glock has released their MHS entrant to the civilian market: the Glock 19X.

It’s got all the Gen 5 improvements: no finger grooves, an improved trigger, and ambidextrous slide stop, plus the texture and replaceable backstraps from the Gen 4 models. By all accounts, the Gen 5 models are awesome. I’m most excited about the improved trigger. It’s better than previous factory models and very competitive with the aftermarket options.

Of course, there are Gen 5 options available for the Glock 19, the Glock 17, Glock 34 MOS, and Glock 26 out there already. The Glock 19X is different. It pairs the full-size frame of a Glock 17 with the compact slide and barrel of a Glock 19.

Glock made this design to fit the “box” of the MHS size specifications. It will probably do well on the civilian market, as short-slide, full-size grip 1911s, snubnosed K-Frames, and subcompact pistols with grip-extending magazines are very popular.

I’m not a fan of the 19X from a concealment perspective, because the height is more annoying to conceal than the length. If I’m going to carry a full-size grip, I might as well get the sight radius of a full-size gun. Plus, those tend to recoil a little softer. I’d be a little more interested in a Glock 19 frame with a Glock 17 slide and barrel for concealment, but that’s just me.

However, if you wanted to build an Open Glock, the Glock 19X is a great base gun. It just needs an MOS model or some milling for an optic. The shorter slide means that if you opt for a smaller compensator like the KKM or Black Rifle units, your pistol will fit in a Glock 34 holster. So you’ll be able to find a holster quickly and cheaply. With a bigger compensator like the SJC, you’ll still have a shorter overall pistol to help transitions, plus a lighter slide that improves recoil characteristics.

You also get the longer, Glock 17 grip. This is nice partially because I prefer the grip on the Glock 17. Your mileage may vary. What doesn’t vary are the magwell options. There are a wide variety of large, competition magwells available for the Glock 17 size frame. Small differences make these not viable for Glock 19s. Bigger magwells are more forgiving than small ones. Plus, there are a wide variety of materials (and therefore weights) available.

There you have it. A concept with plenty of admirers, albeit for different reasons. It’s good to see more options.

A Cruiser By Any Other Name

I’ve discussed before that the Arleigh Burke-class is the best destroyer afloat today. It’s got a good radar, plenty of missile capacity, and comes at a pretty reasonable price due to its large production run. Competitors like the Daring class cost entirely too much and deliver entirely too little. Let’s look at a a follow on. Nothing lasts forever, and something newer, with newer systems, will be fun to sketch. This will be my version of something like the Zumwalt class. Though, because I prefer things evolutionary, it will be rather less ambitious. Admiral Zumwalt would have wanted it that way, anyway.

We’re not going to compete directly with the Burkes in terms of size, because that makes it really hard to justify the changes. And we’ve already sketched smaller. In case the title didn’t give the game up, we’re going bigger.

As always, we must first define our mission. Being a large cruiser, we’d like it to focus on air defense and air control, with plenty of land attack capability (i.e. plenty of missile tubes). We’d also like reasonable antiship capability and some antisubmarine capability, though this last is negotiable. I’ll pencil in some nice, off-the-shelf sonar systems now, with the understanding that designers can make adjustments as needed for cost reasons there.

On to the sketch! First thing to do is to forget about the stealth nonsense baked into the DDG-1000 design. Some low-observability features are a good thing, but the excessive stealth optimization of the Zumwalts with their special superstructure and ridiculous tumblehome hull is silly. A more normal hull design, bow raked forward, has far better seakeeping, and that’s much more important. Not only is it a patently obvious ship if one bothers to look out their windows, but we’d expect it to be able to handle Air Defense and Air Control, which means the radars have to be on, which means it will be pumping out electrons like the Las Vegas strip. And if we don’t turn on the radars, what exactly is protecting the carriers? Accepting that not every new design has to be a ghost’s shadow will help keep costs down. We need to limit the use of new technologies in new designs so the costs don’t explode. Nobody bats 1,000 with new designs. Some will fail, and we need to be resilient about this. Also, a more conservative design means we’ll be able to reuse some things from existing designs. Or, test out some new stuff elsewhere. Like we used to.

There you have it. Some gentle angles, avoid corner reflectors, keep the nice clipper bow. As a side effect, that’s a lot prettier.

Next: radars. I really like the original, un-neutered suite planned for the Zumwalts, namely the SPY-3 and the SPY-4. The SPY-3 is an X-band AESA radar, optimized for best tracking accuracy. The SPY-4, deleted from the DDG-1000s to save costs and still fitted on the Ford-class Carriers, is an S-band AESA radar optimized for high volume search. This split of functionality mirrors what NATO testing found to be best in the late 90s. These were integrated into a dual-band array system, which is some pretty revolutionary stuff. I’m fine with that as one of the key new technologies embarked, though the emitters could also be separated. The overall concept is right though. And, of course Aegis-type integrated fire control and combat management systems.

As a bonus, from an emissions perspective, a cruiser with a dual band radar looks a lot like a carrier with a dual band radar. Or maybe that other contact is another cruiser and the carrier is somewhere else. Or has its radars off. Emissions doesn’t tell you. With the right ECM and radar signature management, your active radar won’t help you either at range. Better go look, and hope you can radio your buddies back before you eat a missile.

On to missiles, and the tubes that launch them. The Mk. 57 can handle a greater volume of exhaust gasses than the Mk. 41, but the sheer number of deployed Mk. 41 tubes means missiles will be developed for that. Also, while the Mk. 57 is a bigger tube, it’s not much bigger, and there’s no missile around that would not fit in a Mk. 41 but would fit in a Mk. 57. Plus, the Mk. 57 modules are rather bulkier than those of the Mk. 41. So Mk. 41 it is! And we’d like to pack her with missiles. To hell with 80 missiles on nearly 15,000 tons. If we can’t do better than the 128 cells of a Ticonderoga, we should go home. Ideally we’d fit four of the big 64-missile clusters off the Ticonderogas for a total of 256 missile tubes. This gives us plenty of space for SAMs, including ballistic missile defense capable ones, LRASMs, Tomahawks, and VL-ASROCs.

Now, let’s talk about the gun. DDG-1000 originally had an ambitious vertical gun with guided shells, but this was shelved. The impact of development costs remains on the final design. I am not sold at all on ambitious gun projects that aren’t railguns, and those are nowhere near ready. The best estimates on the range of the Advanced Gun System put the ships entirely too close to shore. I’m fine with 155 mm, but 155 mm without being able to share shells (and shell development projects) with the army is patently absurd. And I’m still not entirely sold on the need these days, given how many other options there are for getting firepower on the beach, and how nasty coastal defenses can be. For my design, I’m quite satisfied with the 127mm/64 LW gun from Oto Melara. 127mm is a pretty standard naval gun caliber, and there are plenty of guided shells in that caliber under development.

There’s no need for extra antiship missile launchers given plenty of VLS cells and LRASM, so we don’t need to worry about those.

Point defense duties will be handled by at least two Rolling Airframe Missile launchers, mounted, well, wherever there’s room. Possibly amidships. Possibly fore and aft, which is rather more traditional.

Since we’re not obsessing over stealth, we can throw in some remote weapons stations and pintle mounted heavy machine guns to hose down any suicide bombers. Who will have no trouble finding a stealth boat because they use their eyeballs, not radar.

For propulsion, we’re going to go for Integrated Electric Propulsion, which has also been done on the Zumwalts. And could have been tested somewhere else. There’s no reason why it should be hard. Generators are run by diesel engines and gas turbines, and electric motors drive the screws. I’d like to take some time on a demonstrator to explore steerable propulsion pods for the electric motors in a military context, specifically focusing on cost, agility, and noise.

Helicopter fit is the usual hangar for two SH-60-size birds and beartrap-equipped deck. No reason to change it. Though, given the size, we should probably expand the hangar a bit to accommodate several drones.

Antisubmarine warfare is not our focus, but we should make a bit of effort to be prepared. A nice bow sonar and variable-depth towed array will do nicely, as will the usual pair of triple 325mm torpedo tubes amidships. Something like the Thales UMS 4110 CL sonar for the bow and a Captas 4 in the towed role.

M1 CATTB

The Component Advanced Technology Test Bed was another late 80s American test program to investigate new systems for future tanks. As we’ll see, it looked quite a bit different from the TTB, and where the TTB was testing a very specific change (namely the unmanned, low profile turret) the CATTB tested a variety of new technologies in a more conventional layout.

CATTB

CATTB shared an Abrams hull, but the turret was new, and came with a bustle-mounted autoloader. The autoloader was very similar to the one on the Leclerc or K2. A new gun was tested, the XM291, which came in both 120 mm and 140 mm versions. The 120 mm version provided a lower-risk alternative to the 140 mm. The turret had rather large forward armor arrays, plus reasonably thick side arrays and a decent amount of roof protection. And I have no idea why they decided to mount so many smoke grenade launchers on there, but they did. This was before the advent of soft-kill active protection systems, but might not go amiss on a tank today with the right cueing system.

CATTB Rear view

As you can see from this rear view, the CATTB also came with a new engine: the XAP-1000 diesel. The Cummins/Allison XAP-1000 was based on the advanced Cummins XAV-28 V-12 diesel, a low-heat rejection engine. It used only oil coolant and has no water in the cooling system at all. Higher temperature exhaust gasses were tapped to run the APU. I don’t know a ton about this engine, but the US Army has a history of backing highly advanced diesel engines that end up being problematic. I would suspect similar things with the XAP-1000. Again, the project went nowhere. Later in the 90s, the Abrams was going to get a new engine as an offshoot of the Crusader project, but the proposed engine was not the XAP-1000. Instead, a gas turbine was chosen.

CATTB is a lot more of a conventionally designed tank. I do really like its lines. The project which was supposed to lead to the Block III MBT ended up leading nowhere due to changing priorities. Though, it is not at a museum. It is in the long term storage section of the Sierra Army Depot in Hurlong, CA. Make of that what you wish.

On the 140mm Tank Gun

Let’s talk some more about the 140 mm tank gun, that late cold war weapon that never was. Perfect for killing Soviet Supertanks that never were. And making your new tank way cooler than everyone else’s. The fastest way to get more armor penetration is to just build a bigger gun with more muzzle energy. A lot more.

As you might imagine, a 140 mm round is quite a bit bigger than a 120mm round. Let’s take a look, because these numbers are damned hard to find:

First, a typical 120 mm APFSDS round for the era, the American M829A1. The legendary Silver Bullet that slaughtered the tanks of Saddam’s Republican Guard. Some variations in length and weight are to be expected amongst 120 mm rounds. Newer rounds are a little heavier, but the size is constrained by ammunition storage racks and the existing chambers. The M829A1 is also the round that was in service while the 140 mm was under development.

M829A1 120 mm APFSDS
* Length: 984 mm
* Weight: 20.9 kg (46 lbs)

And now, the round to replace it. Producing 23 MJ at the muzzle, more than double that of the 120mm. The mighty 140. Dimensions were fixed by the NATO countries that were all developing their own versions of the round.

140mm tank round

XM962 140 mm APFSDS
* Length: 1,482 mm
* Weight: approximately 40 kg (88 lbs)

The length and weight of the 140 mm stand out. This round would have been a royal pain to handle. It’s also a bit fatter, so autoloaders could handle fewer rounds. This explains why the K2 Black Panther, otherwise similar to the Leclerc, can only hold 17 rounds in its autoloader compared to 22 in the Leclerc. The K2 is ready for 140 mm, needing only a barrel change. Interestingly, the round count in the Black Panther matches those for the M1-CATTB prototype, which had a similar, belt-style autoloader in its bustle. Don’t worry, we’ll talk about the CATTB in a future article.

NATO-standard 120 mm rounds like the M829A1 are unitary rounds. One big piece, like an oversized version of the cartridges you load into your guns at home. Because of the large size of the 140 mm rounds, these were made as two-piece rounds. Unfortunately, while I can find dimensions for the round’s overall length, I don’t have dimensions for the pieces. Until I can find one to measure myself, we’ll have to make do with some pixel counting/scaling, which yields a length of about 1,024 mm for the upper part of the round, and about 461 mm for the lower part. Which is still big and annoying for autoloader development. Length of the upper part of the round is heavily influenced by the length of the APFSDS projectile. This also would affect a design using a carousel autoloader like the TTB, since carousel (and therefore hull) height and turret height are constrained by the requirement to lift and rotate the rounds into position.

Based on the standards of the day, the 140 mm gun made more than twice the energy of the 120 mm at the muzzle. Of those 23 MJ of muzzle energy in the 140 mm, 14 MJ goes to the penetrator. Running the numbers meant that the 140 mm APFSDS could punch through more than 1,000 mm of RHAe at a ‘battle range’ of 2 km. For comparison, we’ll pull some open source estimates for M829A1, which give it a penetration of 700 mm of RHAe1.

Now, those are some really good numbers2. Of course, there’s a price to be paid. Even with the two-piece construction, everyone working with the 140 mm designed with autoloaders. Which meant significantly reworked turrets for the British, the Germans, and the Americans at a minimum. Plus, ammunition capacity would drop.

Upgunning to a 140 mm round was the simplest way to get a lot more armor penetration capability into a tank. At least from a weapon/projectile design standpoint. It would have required some serious reworking of then-extant designs, but such is life. When the Soviet Union imploded, the armored threat of the projected Future Soviet (super)tanks evaporated, and the 140 mm gun projects were quietly shelved. 120 mm rounds are continuing to get more development and the latest are quite a bit more effective than the M829A1. Lower cost, likely lower capabilities, but this decision makes sense given the circumstances.


  1. There’s some variation in this estimation depending on source. Open source disclaimers apply, etc. 
  2. They’re also a trifle disingenuous. Nobody is armoring their tanks with a meter of rolled homogenous steel. Literally nobody. A more advanced penetrator design can exploit effects on the not-steel that people actually armor their tanks with. Similarly, the armor might be designed to radically degrade (read: break up) the penetrator, which can be sort of but not really captured in RHAe estimations. So the RHAe numbers don’t actually tell the whole story on either side of the design puzzle. Oh, and the numbers themselves are the usual open-source estimates3, so they’re probably all wrong. 
  3. If you’d like to try your hand, start running through the Odermatt equation. And then remember that Odermatt wrote for tungsten-based penetrators, and M829A1 is depleted uranium, so you’ll need to tweak it. 

M1 TTB

The M1 Tank Test Bed (TTB) was a late-80s prototype to test unmanned turret design concepts and compare them to a modern, manned-turret design: the then-state-of-the-art M1A1. The TTB was not necessarily intended to be what the next MBT would look like, but it was intended to shake out some design concepts and see if they were worth considering in the future. So let’s take a look.

m1 ttb

Some of you may notice a resemblance to the T-14. Both use similar unmanned turret design concepts. Such designs have been kicked around since the 1950s by many different groups of tank designers, and all for similar reasons of being able to reduce protected volume (and hence reduce design weight for a given standard of protection). The M1A1 weighs about 57 tonnes. The TTB, with a similar protective standard and the same 120mm gun (and a similar ammunition capacity) was reckoned to weigh about 15% less, for an approximate TTB weight of 48.45 tonnes. Interestingly, this is very close to the published weight for the T-14.

TTB also, of course, reduced crew to three men and put in an autoloader for ammunition handling. The design was intended to improve crew safety by completely isolating the crew from the ammunition. The autoloader itself was a large carousel, holding all ammunition below the turret ring. Let’s look at some pictures.

ttb autoloader

It’s sort of like the autoloader on the T-80, though NATO 120mm ammunition is one-piece, and is therefore a little more annoying to design an autoloader for. The autoloader built for the TTB held 44 rounds and this could be expanded to 48 or even 60 rounds with minor design changes. All of the ammo was stored in a ready configuration because the crew would be unable to move ammunition from a reserve magazine to the autoloader’s ready magazine (as on the Leclerc for example). The TTB autoloader was extensively tested, and could manage a rate of fire of one round every 12 seconds. Spent case bases or misfired rounds were ejected out a small hatch the back. The autoloader could be supplied through the rear hatch, and also had an unloading mode where it could slowly present rounds for removal. The autoloader weighed about 1,400 lbs. empty.

Some might question the vulnerability of such a design. However, statistically the vast majority of tank hits occur to the turret. Tanks like the T-72, for example, ran into trouble because of the ignition of their unprotected reserve ammunition stowage in the turret, not hits that set off ammunition in their autoloaders. And again, complete isolation from the ammunition should keep the crew relatively safe.

The TTB program was dialed back with the end of the cold war and was finally cancelled in the mid 90s. The autoloader design was used in the M1128 Mobile Gun System version of the Stryker.

As for the TTB prototype, it’s at the National Armor and Cavalry Museum at Fort Benning, and has recently been restored and repainted.

Stage Design Sins

I’ve mentioned really enjoying competitive shooting, but I want to go over some classic screwups. Things that can hinder your enjoyment. Things that stage designers shouldn’t do.

The Sin of Insufficient Time

Par times are necessary parts of stages. Basically, this is a time limit. Par times are good in case one gets in over one’s head, or has significant equipment failure. In general, the RO won’t stop you unless your equipment fails in an unsafe way. If you’re having a bunch of minor issues, you’re going to have a hard time. And par times are necessary to keep things moving and put you out of your misery if everything goes south.

However, par times that are too short lead to large numbers of people timing out. Frankly, if I drove a long way for a match, and some idiot stage designer had misoverestimated the skill level involved, or is trying to compensate for a giant enrollment list with par times, and I time out a lot, and I see a bunch of other people timing out a lot too, than I’m not coming back. Ridiculously short par times promote poor behavior, like giving up. One of the best things one can learn in a match is to not give up if something goes a little sideways. Your plan didn’t work, so you adapt. Too short a par time will encourage you to give up, because you won’t have enough time to try something else. That’s lame.

The Sin of Stupid Hard Targets
In a similar vein, one should avoid targets that are Stupid Hard. Clearly, USPSA Nationals is expected to be harder than your average local club USPSA match, because of the higher average skill of the participants. And there’s nothing wrong with that. That’s how is should be. Tailor the match to the crowd.

The problem comes when stages have segments that are so difficult, your score is improved by firing a round in the direction of the target and then moving on. A 50 yard pistol spinner might be one such example, depending on some other stage particulars. In such a case, it would almost certainly be the correct move for best score to fire a round at the spinner, take the failure to neutralize penalty, and move on. That’s lame.

These are things that can go hand in hand.