Category Archives: Weapons Technology

The Quiet Special Purpose Revolver

We were sure we’d written about this before, but if we did, we can’t find hide nor hair of our previous report. So, just maybe we haven’t. Recently, we got some new information, and will share it with you.

The QSPR is an extremely rare special-purpose revolver that was developed and produced by the AAI Corporation. Formerly Aircraft Armament Incorporated, the name was abbreviated officially because they never sold any of their aircraft armament concepts. They worked on several ill-fated futuristic small arms of the 1960s (like the SPIW) and one very successful one, the M203 40mm grenade launcher.

The QSPR from the original report (the bad reproduction is due to the records being stored on microfilm or microfche).

The QSPR from the original report (the bad reproduction is due to the records being stored on microfilm or microfche).

The QSPR was made from a Smith & Wesson Model 29. Frames in white were provided to AAI by Smaith, and they were modified with a .40 caliber smoothbore barrel and the cylinders were bored out to 0.528″, leaving a minimal web between chambers. (The lost strength was made up for by the strong cartridges). The weapon was innocent of any sights — it was meant to be used at contact range, inside tunnels, although accuracy to 25 feet was claimed (and Vietnam users reported it was more accurate than their .38 revolvers). Both standard large-frame Smith and aftermarket or custom grips were tried.

The gun was issued with a flap shoulder holster and two ammo pouches holding an odd 7 rounds each.

The gun was issued with a flap shoulder holster and two ammo pouches holding an odd 7 rounds each.

The objective was to provide a weapon for tunnel combat, a weapon with reduced blast, noise, flash and yet increased lethality over the standard pistols and revolvers of the era. It was designed to produce a column of lethal buckshot at very close range, with no flash and very limited blast. Noise in the enclosed tunnels was equivalent to a .22LR firearm outdoors, which was a great improvement over the eardrum-shattering blast of the alternative, the M1911A1 .45 pistol.

Eleven QSPR revolvers were made, of which one was retained by AAI (and is still reportedly retained by a successor, Textron systems). Ten were deployed in 1969 for combat testing in Vietnam; one was reported as a combat loss. Of the existing revolvers, apart from the AAI reference piece, two (#5 and an unknown example) are in a US Army museum, and one is in the ATF reference collection. It was the missing Vietnam gun, which was used in a homicide in California and recovered, according to Dockery.

THE QSPR seems very sophisticated for a first shot, and that’s because it wasn’t. A previous S&W based tunnel revolver was a Model 10 M&P with reduced cylinder gap, a suppressor and an aiming light. It was part of a comprehensive suite of gear assembled by the boffins in the Army’s Land Warfare Laboratory and called the Tunnel Engagement Kit, illustrated here. (The vane switch in the guy’s mouth turned on the VC aiming point on his cranium). You can almost hear them saying, “Do bring it back this time, Mr Bond.” But this bit of lab genius was not what the guys needed, and so the boffins went back to the lab and cooked up the QSPR.

Different tunnel rat rig

Ladies and gentlemen, here is a recent photograph of a unicorn — a live QSPR round. This is believed to be the last and only live round in existence (the ATF caused the destruction of most of them maintained by AAI and the military museum system by declaring them suppressors). The material is high-carbon steel, because the case contains the entire energy of the round, inside a piston. An end cap is screwed on the base of the round; threads in the muzzle end act as a trap to catch a piston. A plastic sheath called a “sabot” wraps around the projectiles and is discarded, much like the sabots used with subcaliber projectiles, when the projectile column exits the muzzle. The muzzle end of the round has a silicone (we think) material applied as a sealant.

QSPR Round 01

The round has a dark finish which appears to be some kind of high-tech proto-melonite coating, although most resources describe the ammo as “blued.”

This is a schematic of the round from what appears to have been the final report on the weapon after development and combat testing in Vietnam. The report recommended further improvements and then general issue to Infantry and Ranger units. Those improvements were not pursued, and the firearm was never manufactured.


The high pressure inside the round breaks the “rim” of the piston free of an annular slot that initially retains the piston in the rearward position and forces it forward, ejecting the sabot-contained shot load, until the pressure snaps the piston rim into a similar annular slot positioned to receive it, and drives the “nose” of the piston into the muzzle-end threads. These two engagements arrest the piston’s forward motion. One purpose of the rearward slot is to retain the pistol and prevent it from sliding and ejecting the payload during normal gun handling.

This is the muzzle end of the round. As you can see, the sabot (or the sealant atop it) comes closer to the muzzle than indicated in the diagram.

QSPR Round 03

This is the breech end. As you can see, there are no markings on the round. The revolvers themselves were marked with the S&W trademark, so we suspect the lack of markings on the ammunition was more a reflection of the toolroom nature of the project than in any attempt to make a deniable or clandestine weapon.

QSPR Round 02

The missing detail from most of the reports, the reason the initial report was classified (albeit only at the Confidential level), and the cause of the QSPRs unusually high terminal effect for a handgun was in a material breakthrough. While most open source reports suggest that the projectiles in the shot column were lead, steel or even tungsten (Wolfram to you Europeans), they were actually depleted uranium.

DU is uranium from which the fissionable isotopes have been removed. It is a side product (a waste product, really) of uranium enrichment for weapons production and has a number of properties making t an excellent choice for projectiles.

While the US was developing the QSPR, Soviet scientists were working on similar captive-piston technology. But in the end, the complexity and cost of the system seems to preclude it from ever being made in more than nominal numbers. The ATF’s Firearms Anti Technology Branch has rendered research on this type of weapon in the USA functionally impossible; Russian designers, who have produced a great many widely varied quiet weapons, seem also to have moved on away from this technology.

The resources below are all worth reading but the most valuable is certainly the official report:

ACTIV QSPR Report OCR .pdf

Sources & Resources

Dockery, Kevin. Tunnel Weapon: The Bang in the Dark. Small Arms Review, Volume 5 Number 9. Retrieved from:

Popenker, Maxim. Smith & Wesson / AAI Quiet Special Purpose Revolver / QSPR / tunnel revolver (USA), World.Guns.Ru. Retrieved from:  Note that Max’s report on the QSPR is pretty accurate but his photoshop job has the barrel a tad too long.

Schreier, Conrad F., Jr. The Silenced QSPR Revolver: An Answer to an Age-old Military Problem. Guns and Ammo Magazine, “Ordnance Department” feature, Guns & Ammo Magazine, October 1971, p. 64. Copy: Guns & Ammo QSPR Article .pdf

Weddington, David E., LTC, IN. Final Report: Tunnel Weapon. Army Concept Team in Vietnam (ACTIV), (Linked above).


Plastic Homemade Lowers Under the Hammer

These tests have been on the net for a while, “a while” ranging from 3 months ago to a couple of days. We thought it would be a public service to collect them in a single post.

Note that “impact resistance” is only one type of strength. Here the material must resist both compression and shock, mostly. However, there are some ways of testing the part (even with a hammer) that can cause compression failures. Torsion is mostly not an issue with these parts. Shear comes into play especially with the printed parts, which tend to fail along print-layer lines.

Part I: Printed Lowers: ABS vs Hammer, vs PLA vs Hammer.

Part II: Printed vs Hammer, vs. Cast vs Hammer.

And, Part III: Multiple cast lowers of different materials, vs. printed lowers.

We hope these tests made an impact on you!

And who else is thinking… hmmm. What about a polymer part with a tough internal structure, and an overmold of the rubbery stuff? If you did the overmold when the inner part was still hot-out-of-the-mold fresh, the exotherm from the overmold would probably go a long way to mechanically join the two “layers.”


Another 3D Firearm Approach: Plastic Casting

Here’s the situation: say, you want to test a new firearm or part design, and because you’re iterating rapidly, 3D printing would be ideal. But the mechanical properties of common 3DP polymers, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) are insufficient, and it’s either more challenging or more expensive to print in materials with better mechanical properties, like nylon.

Lost PLA 10-22 receiver. The casting with filler and riser still attached.

Lost PLA 10-22 receiver. The casting with filler and riser still attached.

One answer, that we’ve covered before, is to use Lost PLA casting. (Indeed, industrial specialty printers are made for printing in wax for the very similar process of lost wax casting; small ones are widely used by jewelers, and at least one major investment-casting supplier to the firearms industry uses a pair of large ones every day). But while you can 3D print in your office or kitchen, metal casting requires working with a great deal more heat, and molten metal. And casting itself is a complex knowledge domain with lots of things to go wrong and a wide gulf of tribal knowledge between the amateur and today’s professionals.

So we give up, right?

Nope. Wrong. There are still several technologies open to us, like metal injection molding (which probably made the fiddly bits inside your carry handgun, unless you’re old school). But even that has some complexities, even though it shows signs of integrating really well with 3D printing. Basically, you can do the prep work, but someone with an industrial setup needs to do the actual MIM for you.

How about plastic casting? There are plastics that are a pain to 3D print, but that can be cast at room temperature and atmospheric pressure. Fosscad experimenter FP gave it a shot, and produced some gratifying results: plastic AR lowers that appear to be superior in strength to 3D printed versions.

The difference between plastic casting and plastic injection molding which is how your Smith or Glock frame is made is that injection molding is done under pressure, and casting is done in atmospheric conditions. That means that casting will usually be less dense and will be done with materials that are poured and set at lower temperatures, as a rule of thumb. Molding is commonly used on Hollywood sets and props, for example, but it also has architectural and industrial applications. Both the silicon “rubber” for the mold and the plastic for the castings come in parts that react and solidify when mixed.

Mold silicon and casting plastic

This page on imgur walks you through two complete batches of plastic casting multiple AR lowers using two different molds, one contained in a see-through plastic box and one in a wooden box.

The sequence of events is:

  1. Print and prepare (i.e. strip off support material, acetone-vapor treat, etc.) your lower or other master part (called a “pattern” in casting).cast plastic -- 3DP pattern
  2. Prepare a mold box and place your pattern in it. Include some material to form a pouring inlet, runners or sprues if needed, and an air release hole.cast plastic lower - mold box 1
  3. Prepare and mix the mold RTV and pour it into the mold box. Let it cure. Beware of exothermic reactions.cast plastic lower - mold box
  4. Once the mold has fully set, remove it from the box, and carefully cut the silicone away from the pattern, taking care to neither damage the pattern (you may want another mold; they don’t last forever) nor, especially, the mold.  Cut apart, the mold will have four parts: left, right, bottom, and core. cast plastic lower - pattern out of mold
  5. Reassemble the mold in the mold box.
  6. Mix and pour casting plastic; let it set.
  7. Open the mold and remove the cast lower. cast lower - out of the chrysalis
  8. Repeat as needed.

Initial testing suggests that these lowers are stronger than printed lowers, and there are stronger, more exotic casting plastics available. Some of this testing has already begun. Here’s a lower cast in “Simpact 85A” showing off its ability to be bent 90º and snap back to original position — probably not useful as an actual gun, but could be a stage or stunt prop.

flexible simpact lower

Next week we’ll show you some impact tests of different printed and cast lower materials, done by “Freedom Printing 3D”. These bear out the supposition that some plastics are much stronger than others.

More testing is required to determine the number of cycles the molds can bear before they begin producing out of spec parts.

Some suggestions moving forward.

  1. Rather than cut the mold open after pouring it around the pattern, use mold release compound and a cope, drag and core system to make the mold so it can be disassembled without drama. This would make for faster mold-making. But only testing will tell if this makes a good-enough mold, or if the cut-apart kind is dimensionally/structurally superior.
  2. While using a printed lower is convenient because it’s easy, and it’s also a lower design already modified to strengthen a weaker material, you could use this system on a lower carved by hand.
  3. You could even use this system to duplicate a factory aluminum lower, but the plastic almost certainly won’t be strong enough in what we’ve learned are the AR’s most vulnerable areas: buffer tower, pivot pin bosses, pistol grip boss, and trigger guard “ears.”

Today in Bubba History: Tokarev Sporter

It’s probably not fair to call this the work of Bubba the Gunsmith, because it was the work of professionals, turning what was then an awkward, ugly, unwanted military rifle in a weird caliber into something a hunter might reasonably take afield, and in the process, turning a bunch of ex-Soviet arms dumped by the Finnish Army, which had captured and tried to use them, into dollars — in this case, Canadian dollars.

Globe Tokarev 01

How were the principals of Globe Firearms Ltd. to know that some day original, unmolested Tokarev rifles would be worth real money? For that matter, how were they to know that the uiquitous .303 British round would become a rarity in North America, and the Russian 7.62 mm x 54mm become more popular? You could not have predicted either outcome in the mid-1960s, unless you were an actual clairvoyant — or certifiably insane.

Remarked with customizer and caliber.

Remarked with customizer and caliber.

This gun has now turned up on Gun Broker, with $950 asked, about what a decent condition Tokarev goes for (but there are very few decent condition guns out there — lots of purple-bolt-carrier Century imports, really). You’d have to want this oddball sporter pretty badly to go that much for it, in our opinion.

Condition is very nice. Design of the sporter stock suggests late 1950s to early 1960s.

Condition is very nice. Design of the sporter stock suggests late 1950s to early 1960s.

Up for bid is a conversion of captured SVT40’s. Bought from Finland, Globe Inc. converted the rifles caliber to what the Canadians all used…the British .303. Gun is almost new condition.

The barrel is shortened substantially, and set back so it can be rechambered for the British round. It looks like the new barrel is about 18″, nice for hunting. Rear sight is standard — obviously the elevation marks are now no longer congruent with the changed cartridge — and front sight is a standard hunter’s ramp type.

Globe Tokarev 03

The gas port has been moved way back, which allows most of the handguards to be discarded. (It may do ugly things to function, which was never the Tok’s strength, though. Or it may have solved Tok problems — we don’t know).

System is like an SKS or FAL, a gas tappet whacks the bolt carrier which cams a tipping bolt up out of battery.

System is like an SKS or FAL, a gas tappet whacks the bolt carrier which cams a tipping bolt up out of battery.

The Russian bore diameter should work OK with the British projectiles.

You can see where the tappet comes through the receiver above the barrel.

You can see where the tappet comes through the receiver above the barrel.

This gleaming bolt carrier, incidentally, is what a Tok bolt and carrier should look like — not the sick plum finish of the Century guns. Those seem to have been ineptly re-arsenaled in some Soviet or satellite depot.

This is what a Tokarev bolt carrier is supposed to look like.

This is what a Tokarev bolt carrier is supposed to look like.

The magazine has an unusual marking on it, it looks like a registration mark, maybe from the ill-fated Canadian long-gun registry, a monstrously expensive failure.

Globe Tokarev 08

Does anybody know what that marking signifies?

The Globe Firearms Ltd. sporterized, caliber-converted Tokarev is a rare period piece, a slice of a time where gun aficionados were almost all target shooters and hunters, and military collecting was a small and sparsely populated niche. That alone would make it a good thing to buy, although not at this price.

Heck, you could even hunt with it (although you’d need a lower-cap magazine, most places).

The South Will Rise Again! Be Ready.

That means, keep your musket clean, powder dry, and hatchet scoured — and buy this 1851 Mountain Howitzer. If Johnny Reb comes marching up your driveway, give him a whiff of the grape!

1851 mountain howitzer firing

The gun’s a replica, but a very well made one. It has the perfect gestalt of a Civil War era artillery piece, to be sure.


1851 mountain howitzerAs you can see, the details, like these trunnion brackets, are visibly high quality. 1851 mountain howitzer mount

The gun is designed to be a live shooter. Here’s what the GunBroker auction says about it:

1851 Mountain Howitzer Cannon built to exact spec’s. 3″ bore. Wood is all white oak. All iron work is hand made then blued. Museum quality shootable cannon. You won’t find one nicer than this one.shipping available.

via Cannon Mountain Howitzer 1851 : Other Collectible Guns at

Like any firearm, it carries the DNA of the technology of its period. We find the details beautiful.

1851 mountain howitzer wheel

Personally, if we were preparing a redoubt for When They Come®, we’d want at least a battery of these things, but one’s a start.

These US Civil War and contemporaneous worldwide conflicts saw the last gasp of muzzle-loading, mostly smoothbore, blackpowder artillery, guns that had changed little ashore or afloat since the Napoleonic Wars or the 30 Years’ War. The Civil War saw the emergence of steel barrels, rifling as standard, and breech loading. In the next 50 years artillery would be revolutionized by the recoiling gun-carriage and much more powerful smokeless powders. By the turn of the 20th Century, guns like this would be fit only for guarding sleepy courthouses, village squares, and veterans’ halls; tens of thousands of them would be melted down in 20th Century scrap drives.

As a muzzle loader, it is considered an antique (even though it’s a recent replica). That means it’s exempt from regulation in many civilized nations (although local regulations, and regulations relative to the storage of the industrial quantities of black powder necessary to making it go bang, may be another matter entirely).

It’s not as cheap as a replica of something smaller, like an 1855 Springfield. The auction starts and $9k and buy-it-now is a stiff $14,000 or so. There is a small community of hobbyists, reenactors and dealers who trade in these remarkable pieces.

On the other hand, if you have a big family, you can develop the kids’ self-esteem by drilling them until they master period Service of the Piece drills.

And you can always be That Guy whose house people gather at on the 4th of July, just for the cannon blast. There is that.

How NoDak Spud Polishes an A1 Lower

Here, in real time, NDS’s very efficient Mike polishes one of the company’s outstanding retro lowers. Polishing is necessary before blasting, which is done before anodizing, to allow the anodizing to take evenly and not be blotchy.

NDS is an interesting combination of idea, work ethic, and customer service. You get straight talk, no bull about ship dates, for instance. If they discontinue a product, like their unique “605” upper receiver that cloned modified M16A1 upper forgings that imitated some tens of thousands that were used briefly — and with permission of the Contracting Officer and Contracting Officer’s Technical Representative — to substitute for short-supplied “slick-side” forgings for USAF M16 rifles. (They discontinued it because they were a ton of work for a slow-selling product).

As Mike notes, it’s a small company. Call or email them and you’ll probablt tallk to Harlan, maybe Mike, and when you see the quality of their parts, you’ll be calling back. Almost every customer is a repeat customer. We’ve lost count of the number of NDS lowers we’ve bought (whoever the guy at ATF is that keeps the N-Z section of The List probably knows) but we think we’ve bought six different kinds. 

And, oh yeah, they make AK receivers, which are the class of the field, and a replacement for the crappy plastic AR-18S lower.

To order or look at their product line:

Large-Scale Clandestine Production of Small Arms

There are a number of designs out there for “resistance” type submachine guns that circulate on the net and are available in books. Many are familiar, for example, with P.A. Luty’s Expedient Homemade Firearms: the 9mm Submachine Gun that landed Luty in hot water with Scotland Yard, or with the work of Bill Holmes (a pseudonym); many of these books date from the golden age of the survivalists in the 1970s and 1980s.

These books are not as far-fetched as you might think. In World War II, the open-bolt submachine gun was found to be well adaptable to converted automotive-part and -accessory production lines (in the form, for instance of the M3 and M3A1 submachine guns) and equally well adaptable to cottage industry (in the case of the Sten Mk II). Resistance organizations built their own submachine guns, often modeled on airdropped Stens but sometimes of indigenous design, such as the Polish Bljeskavicza (sp?).

Resistance groups that produced Sten copies included the French, Norwegian, Yugoslav and Greek resistance, and a number of these home-grown subguns grace those nations’ museums. In an unusual twist, Germany produced its own Sten copies of several types (the most well-known being the MP 3008) during its in extremis phase.

In the 1960s, an American went to prison for supplying counterfeit Stens to Cuban exiles for their war on Castro’s socialist workers’ paradise.

One of the books that offers plans for an open-bolt submachine gun derived from Uzi, CZ 23-26 and Sten practice is Gerard Métral’s (an obvious pseudonym) Do it Yourself 9mm Submachine Gunpublished in 1985 by Paladin Press. The meat of Métral’s publication is sixty-odd dimensioned drawings of parts, which if fabricated and assembled would produce a crude 2nd/3rd generation open-bolt submachine gun, but he also addresses clandestine serial production, as opposed to the one-off manufacture of hobbyists. Here’s an extract of that bit of his book:


These basic principles can be explained by the following joke, believed to have been originated by Jews in Palestine during the last months of the British mandate.

A poor man was working in a plant named Sewing Machines, Inc. He wanted to give to his wife a sewing machine but had no money to buy one, so every evening he’d smuggle home a different piece that his factory was making.

After many days his home stock was complete, and he tried to assemble the machine for his wife. He tried many times, but he always ended up with a machine gun.

A clandestine resistance organization needs considerable quantities of weapons. The importation of complete guns may be difficult and costly, and a single police operation may undo months of effort.

Such an event happened to the Irish Republican Army, when on 30 October 1987 the Eskund II, a ship loaded with tons of Libyan weapons was intercepted by the French authorities. The method suggested here consists of a decentralized mass production of harmless metallic pieces that may be used for various purposes. All machining operations requiring heavy machine tools are completed at this stage. The parts are then dispersed in several small workshops where they can be completed without special tools or skilled labor.


The clandestine organization needs efficient cover to buy large quantities of metallic components without alarming the authorities. The only way to do this is to control at least three small or middle- sized industrial plants used for subcontracting work and with a regular output of some kind of mechanical devices.

You must have a net of interconnecting enterprises devoted to the decentralized production of mechanical devices. The idea is that the orders and movements of the gun components will be completely hidden in a stream of civilian goods.

It is also assumed that you observe all the basic rules of security for a clandestine organization.


Many components of the submachine gun could belong to any civilian mechanical device, and no one would likely suspect their final destination, at least in their half-finished state. I call these elements “general-purpose pieces.” The clandestine organization may order them from ordinary factories. The springs used in the gun are good examples of such pieces, as are the plugs and support rings.

Salami-principle sear

Salami-principle sear from partially-prefabricated bar stock.

Other components are to be made in two steps. First a bar is machined to the correct profile in an industrial factory. The longer the bar, the better the camouflage. These bars are then dispersed to the smaller workshops, where they are cut like an Italian salami. Most of the resulting rough cuts require only a few drillings to finish the piece. I call these parts “salami-principle pieces.” The sear, the bolt, and even bolt carrier are such pieces.

The receivers and trigger mechanism housings are taken from commercial steel tubes and U iron, which appear innocuous. Once the work has begun, it will be difficult to conceal the parts’ ultimate function. Fortunately, this phase is done quickly, even in small workshops. For your security, you must remove the pieces from the workshop as soon as they are machined.

The pistol grip, either in its metallic-and-wood or plastic version, is a compromising piece. You have to build it in a secure place. Because it doesn’t require special machine tools, it is possible to manufacture it in private homes.

The barrel is the most critical part of the process. For accuracy, a gun must be rifled. As indicated above, it is possible to rifle a barrel with primitive tools, but this is inadequate for a large-scale production. You must therefore find a way to smuggle industrial barrels. I recommend importing finished barrels whose cartridge chambers have already been machined. To smuggle these components, it is wise to use the ant strategy; i.e., import a small number of pieces over and over. It will minimize loss in case of interception and deflect suspicion of a large-scale operation. Barrels can be easily concealed in metallic pipes, imported as bars, or hidden in a truck chassis.

Magazines should also be purchased from industrial sources.

Final assembly should also be done in a secure place. Since the quality of manufacture is difficult to control under clandestine conditions, only after the final assembly will it be possible to test whether the guns work or not. Therefore, you must have a place to fire the guns, without alarming the whole neighborhood, with an adjacent workshop to make the final corrections.

An important element in this production scheme is theTh distribution of jigs and tools to the various manufacturers, especially for the small pieces.

Buying barrels or magazine is not practical, of course, for truly clandestine manufacture in a denied environment. To truly have a clandestine arms factory you must be able to make these difficult parts, and you must also be able to make ammunition.

To keep such a factory in the face of a hostile intelligence or security service requires full-on tradecraft, including isolating links such as cut-outs, and clandestine communications and logistics. It’s a tough set of conditions to meet, especially behind enemy lines. But we can learn a little from the organized criminal enterprises that have done this before, and a little from the resistance organizations that have done this before, and we can apply logic and reason to the problems that might arise.

Mossberg .22 kB!

This is what an out-of-battery fired .22LR round looks like, afterwards.

rimfire kB!

Minus, of course, any parts still embedded in the shooter.

You can see what looks like a light firing pin strike at about 4 o’clock. It probably looks light because it was light, because the rim was not fully supported by the chamber when the striker or firing pin struck the case head. But it was supported enough for the primer to fire, with the results you see here. Lucky the shooter wasn’t left-handed, or he might have been plucking that brass out of his face.

From /r/guns:

Was shooting my mossberg 702 (i know get the 702 bashing out of your system if you need to) that i have put a couple thousand rounds through since i have had it, this particular rifle always had minimal malfunctions for me and that is why i held on to it. Most of the time a little spray of clp and it will keep running fine. But today i was shooting federal bulk pack and all was going well until this round exploded and sprayed my hand with debris.
My assumption is that it was not fully into battery when i pulled the trigger resulting in the casing basically banana peeling and ripping in half.
Moral of the story is the value of safety glasses because who knows what kind of shit would have been sprayed in my eyes.

via This is why we wear safety glasses : guns.

A gun shouldn’t be able to fire out of battery. We mean, it should be physically impossible, if the designer was remotely competent. John M. Browning’s guns have safe designs that will not fire out of battery, and he’s been dead since Silent Cal was President.

We don’t know if the gun was stock or modified. There are a number of instructions for doing a Bubba job on the Mossberg 702 / 715 trigger mechanism on the net, for example here’s an Instructable on it. Owners who hack a trigger they don’t understand — and anybody who writes about the “seer” probably doesn’t understand — are the sort of thing that gives gun-company lawyers sleepless nights. One of the things that can cause out-of-battery firing is an improper trigger mechanism, which can be caused by bad design, manufacture, or subsequent modification. Disconnecting or blocking the firing mechanism until the bolt is fully seated is a fundamental requirement of trigger mechanisms.

Without doing surgery on a sample of 702s, ideally including the mishap firearm, we can’t say what provisions are made for safing the gun until complete bolt closure, or why they failed in this case.

The Circular Torpedo Run

If you know anything about naval torpedoes, you’ll understand instantly why a circular run is A Bad Thing. US torpedoes in World War II were prone to circular runs — and that was not even one of our tin-fishes’ top three problems.

Since Whitehead’s invention and/or popularization of the self-propelled torpedo in the 19th Century,  every sea power on Earth worked on these weapons, and by the outbreak of World War II each maritime power thought their torpedoes were the best.

The Japanese, dismissed by racialists in America and Europe as bucktoothed, nearsighted monkeys copying Western design, had come up with both maritime and aerial torpedoes that were miles ahead of any other nation’s. These were principal armament on cruisers and destroyers, outranging the cruiser’s guns and able to sink a capital ship with a single hit (try that with a 5-8″ gun. Not happening). They also armed Japanese subs, and lightweight versions armed world-class torpedo planes. American and British battleships and carriers would feel the lash of these devices in the opening months and years of the war.

The British, Italians and Germans entered the war with effective torpedoes that they had justifiable confidence in, and could launch from warships, patrol boats, or aircraft. (So did the French, but in naval terms they were a footnote to the war).

The US was, in American fashion, the most confident in its torpedoes, but the actual devices were not world class, they were not reliable, had a short range exposing launch platforms to enemy fire, were not accurate, and the most serious problem of all, they tended not to detonate. Weapons safety is all well and good, but it’s not supposed to be safe any more when you manage by industry and luck to overcome all its other flaws and  bang it on the side of an enemy warship. And our torpedoes were safe, and our ordnance officers dismissed complaints about it well into the war. 

A generation raised on movie westerns went to war as the good guy in the white hat, but with an empty revolver. So the black hats won a few.

The three problems with the US Mk. 14 torpedo at the start of the war were:

  1. Depth control that didn’t;
  2. A contact exploder that didn’t;
  3. A magnetic exploder that didn’t, which was replaced by an “improved” version that did, about fifty yards before it got to the enemy target.

In one lucky, harrowing attack, USS Tunny under John A. Scott, which had had a miserably failed war patrol due o non-firing contact exploders, found itself on 9 April 1943 in the middle, literally, of a two-carrier Japanese task force. Scott daringly placed the boat midway between the two columns of the Japanese force, firing his six bow tubes at one carrier and its escort and four stern tubes at the other, at very short range. The carriers escaped, Ultra/Purple intercepts later revealed (although they were not declassified until decades after the war), because the torpedoes blew up short of the target.

The Battle Flag of USS Tang -- a panther breaking through a Rising Sun.

The Battle Flag of USS Tang — a panther breaking through a Rising Sun. From The Last Torpedo.

As far as circular runs go, there are 24 known incidents1. (It is possible some of the subs on Eternal Patrol also fell victim to circular runs, although the circumstances of most sub losses have been corroborated by Japanese records). In 22 incidents, the launching vessel evaded the torpedo. In two, we know it sunk a submarine because USS Tullibee and USS Tang had one and eight survivors respectively from their crews of approximately eighty officers and men. Here’s what it seemed like to a sub crew:

On the bridge, Bill Leibold scanned the waters with his binoculars. He stood next to O’Kane. Suddenly, he saw the last torpedo, Number 24, broach and then begin to porpoise, phosphorescence trailing it. A few seconds later, it made a sharp turn to port and then, unbelievably, began to come about.

“There goes that one! Erratic!” shouted O’Kane.

The last torpedo was now heading like a boomerang, back to its firing point…back toward the Tang. Something had gone terribly wrong. Perhaps its rudder had jammed or the gyroscope in its steering engine had malfunctioned.

“Emergency speed!” cried O’Kane.

Below, twenty-year-old Motor Machinist’s Mate Jesse DaSilva had just left his post in the engine room, having decided to get a cup of coffee. He was standing with one foot in the mess. Over the intercom, he could hear the bridge crew react as the torpedo headed back toward the Tang.

“Captain, that’s a circular run!” he heard Leibold say.

“All ahead emergency!” shouted O’Kane. “Right full rudder!”

“Bend them on,” added O’Kane. “Control, just bend them on.”

In the engine room, Chief Electrician’s Mate James Culp did his best to comply, knowing the Tang needed all the power she could get if there was to be a chance of saving lives.

The torpedo was now making straight for the 300-foot submarine. The men on the bridge stood, transfixed, their eyes “popping out of their sockets.” The Tang was moving at about 6 knots, 20 less than her final torpedo.

“Left full rudder!” ordered O’Kane.

Bill Leibold watched in stricken silence as the torpedo headed right at them, coming dead-on toward the Tang. Then he lost sight of it as it continued down the port side.

Maybe it will miss. Maybe it will veer away and begin another erratic circle. Maybe the Tang will evade just in time….

In the conning tower, Floyd Caverly waited like the other men for the inevitable.

Surely there is enough time to get out of the way—to get thehell out of here? Surely?

Speed. Speed is all we need…just enough to get out of the way. If only the Tang would just set by the stern and set off like a speedboat.

But the Tang was not a speedboat. She could not avoid the charging torpedo. It hit the Tang ’s stern with a massive explosion somewhere between the maneuvering room and the after torpedo room, killing as many as half the crew instantly and flooding all aft compartments as far forward as the crew’s quarters, midway along the boat.

Caverly was standing looking at a radarscope when it happened. He…thought that the Tang had been snapped in two. The waves of concussion from the explosion made him feel as if he were experiencing a massive earthquake. He did not know which way to step to catch his balance. The deck plates rattled and shook. Lightbulbs went out.

In the conning tower, there was chaos.

“We’ve been hit!” cried Executive Officer Frank Springer.2

USS Tang sank in minutes; a few of the men in the conning tower, and a few of the 45 who made their way to the forward torpedo room to attempt to use the forward escape trunk, were the only survivors. (The after trunk was destroyed by the torpedo). The next day, angry Japanese convoy escorts picked up nine survivors from the submarine that had devastated the convoy they were guarding.

Damage analysis, originally classified Confidential, of Tang wreck.

Damage analysis, originally classified Confidential, of Tang wreck. From War Damage Report Nº. 58, 1 Jan 49, hosted at HyperWar.

It turns out the cause of the circular runs was a combination of failed design and human error (although Newpower discounts the design problem). If a torpedo was assembled with the gyro in wrong, or was launched without the gyro installed, it would circle. That problem was not discovered until a sub, USS Sargo, survived a circular run only to have an embarrassed torpedoman find the fish’s gyro still in a case aboard the boat. It did not even occur to anyone at the Navy’s insular, smug torpedo establishment that a torpedo that could kill everyone aboard if one junior rating made one simple error just might be a design problem.

It is an essential principle of machine design that something that can be assembled wrong, will be assembled wrong.

The US Navy did not have working torpedoes until late in the war, when torpedoes designed by private industry came online. The torpedoes designed and built at the Navy’s Torpedo Station in Newport, RI never worked entirely right. But even as submariners and PT crewmen knew the things were no good, the ordnance men were certain they were the best in the world, and weren’t interested in listening to complaints from the field.


  1. That’s Newpower’s number, 24. The original list at Ed Howard’s submarine history site comprised 21 possible circular runs, which after adding 8 more provided by Charles R. Hinman of the sub memorial site, comes to 29.


Howard, Ed. Instances of Circular Running Torpedoes Reported by U. S. Submarines during World War II. Retrieved from:

Kershaw, Alex. Escape from the Deep: A True Story of Courage and Survival During World War II. Philadelphia: Da Capo Press, 2008.

Kershaw, Alex. The Last Torpedo. America in WWII, June, 2008. Retrieved from: (note: this is an excerpt from Escape From the Deep). 

Newpower, Anthony. Iron Men and Tin Fish: The Race to Build a Better Torpedo during World War II. Annapolis: Naval Institute Press, 2006.

Thomas, Russell. The History of the Torpedo and the Relevance to Today’s U.S. Navy. History.Navy.Mil. Retrieved from:

US Navy. War Damage Report Nº. 58. Submarine Report. Section X: USS Tang (SS-306). Retrieved from:

The Problem with Overmatch as Defined as “Range”

Recently we discussed Jim Schatz’s 2015 NDIA presentation, in which he suggested that US had lost infantry firepower “overmatch,” which he seemed to define as “longest effective range.” His numbers were fuzzy, with three different ranges for the SVD (one of them being 1500m, and we can’t believe that Jim hasn’t shot an SVD or the better-finished, reverse-engineered Chinese NDM-86), but we had several issues with his concept.


Today, let’s talk about another issue, and that’s the single-point nature of effective range as a measure of firepower.

Here’s a historical example. We would guess that most of the readers of this blog have fired, at least for familiarization, an AK and/or its civilian clones, and an M14 and/or its civilian clones. And most of you, then, would be comfortable that the M14 outranges the AK considerably as a practical matter. This is not only due to the design decision to use a full-house turn-of-the-20th-Century rifle/MG cartridge in the US 1950s design relative to the design decision to use a classic mid-century intermediate cartridge in the AK, although that’s a big factor. But the M14 also has considerable advantages in ergonomics and especially sights. The AK still has a 19th-Century open sight, like a 1891 Mosin-Nagant or 1898 Mauser, just shortened to the extreme practical range of the AK, and has a very short sighting radius (which is not entirely a bad thing, for combat marksmanship, but is a real detractor on the rifle range or when engaging enemies at the rifle’s extreme range). The AK, with a similar weight and much less impulse in every cartridge, has superior numbers on recoil and is more accurate in automatic fire from unsupported positions. (Not to say that it’s accurate in objective terms or relative to semi-auto fire, just that it’s far better on full-auto than you can expect any 7.62mm full-auto service rifle to be, and that therefore one can train to fire it automatically accurately, given instruction and/or ammo).

In Vietnam around the end of 1965, US forces first engaged disciplined, regular troops of the North Vietnamese Army in the bloody battles of Ia Drang. The enemy’s ‘arm of choice’ was the AK47. General Wheeler’s ‘worldwide’ trials had shown the AK to be ‘clearly inferior’ to US weapons, and most US soldiers at that time had shown a preference for the M14 over the then-AR-15. But that was 1962 and peacetime, and this was 1965 and counting. America was at war in the jungle, again.

When US forces armed with the M14 encountered light, mobile Vietcong forces armed with the SKS-45 and AK-47 in Vietnam, the result was not Americans crowing about the superiority of their rifle, but Americans demanding a light, short assault rifle with a 30-round magazine, like the AK.

An AK cutaway from the Czechoslovak satellite Army Technical Illustrated Magazine (ATOM in the Czech acronym). The CSSR wss the only satellite country to reject the AK.

An AK cutaway from the Czechoslovak satellite Army Technical Illustrated Magazine (ATOM in the Czech acronym). The CSSR wss the only satellite country to reject the AK.

If effective range is just one axis on which firearms can be compared, and other axes include ergonomics, controllability, convenience of reload, quantity of ready ammunition and basic load, weight of gun and ammunition. Almost all of these are subject to being improved, and, unlike effective range, not all of them are entirely dependent on cartridge selection.

Cartridge selection is a decision that is not only technical, but also logistical, and, for a nation that often fights alongside allies and coalitions, inherently political. Gun buffs may not like these facts, but they are facts. When the US goes its own way (as it did with M16 adoption in the 1960s) it puts considerable stress on its alliances, particularly after it had already bullied one international alliance and several nations with strong bilateral alliances with the US into accepting the 7.62 x 51mm NATO cartridge mere years before.


  1. From The Black Rifle: M16 Retrospective. Toronto: Collector Grade Pubs., 1987. Quoted in Bruce, Robert. M14 vs. M16 in Vietnam. Small Arms Review. Retrieved from: