Category Archives: Weapons Technology

Imura-san gets the shaft — two years’ imprisonment

3D imuras guns

Imura’s printed guns, seized along with his computers and printer when he was arrested.

Japanese 3D-printing gun activist Yoshitomo Imura was convicted and sentenced to 2 years in prison for printing guns.

The Yokohama District Court handed down the sentence to Yoshitomo Imura, a 28-year-old former employee of Shonan Institute of Technology who made a number of guns with a 3D printer in his home in Kawasaki outside Tokyo last year.

Imura was arrested in May on a charge of illegal weapons possession in what media reports described as Japan’s first such case involving 3D-printed firearms.

In a very Japanese ruling, the judge seemed as upset with Imura-san’s nonconformity as he was with the guns, and condemned Imura for “flaunting his knowledge and skill”:

“This has shown that anyone can illegally manufacture guns with a 3D printer, flaunting their knowledge and skill, and it is an offense to make our country’s strict gun controls into a dead letter,” public broadcaster NHK quoted judge Koji Inaba as saying in the ruling on Monday.

Prosecutors had demanded a prison term of three and a half years for Imura. Defense lawyer Akira Noguchi had argued that Imura did not know his acts were illegal. After the ruling, he said that an appeal had not been decided upon yet.

via 3D-printed gun maker draws jail term in Japan | PCWorld.

Imura's Zig-Zag Revolver. He only fired it with blanks, but that didn't keep him out of durance vile.

Imura’s Zig-Zag Revolver. He only fired it with blanks, but that didn’t keep him out of durance vile.

Despite the legal findings, our information is that Imura designed and manufactured his “guns” to fire only blanks, which are available in Japan in calibers and cartridges that have no commonality with any live ammunition, like the 8mm blanks popular in Europe.

Mind you, we understand why Japanese officialdom gets upset when the subjects start “flaunting their knowledge and skill.” The last time somebody tried that, his name was Isoroku Yamamoto and he wound up getting their country nuked.

What TrackingPoint Must Do to Sell to SOF

Tracking Point ProductsWe think the guys running TrackingPoint know what they have to do. In fact, we think they’re already doing these things. But here’s what, from our point of view, is missing from the current iteration of TrackingPoint hardware and software for real penetration into the upper tier SOF market.

So, Who Do You Hit First?

SF Recruiting Poster pick it upIf we were their marketing consultants (we use our MBA, but not like that), we’d also press them to focus on sell-in to certain SOF elements that are image leaders in the international SOF community. Sell, for example, to SAS, and you will have Peru, the UAE, the Netherlands, and many other nations very interested in your product line (Indeed, sell to SAS or to their US counterparts, and you’ll get sale after sale, worldwide). It’s important, also, not to over-discount the stuff to your lead customers: confidentiality agreements are fine and good, but they probably can’t keep, say, American shooters from telling the foreign shooters they’re training with or competing against, what a good deal you gave ‘em.

Another possible launch customer is FBI HRT. As their history of reckless shots and whacked non-targets shows, they could use the marksmanship boost. Meanwhile, despite their record, they’re very influential on local police procurement. Tag/track/release technology is just the ticket for police marksmen who never get enough time for training, and yet have to make more consequential and more constrained shots than a lot of military snipers. (A military sniper, outside of some rarefied CT or HR gigs, almost always has the option to no-shoot. FBI or police sniper, scope-on a crim threatening a hostage, might lack that luxury).

Who Don’t You Hit?

While the Marine Scout Snipers could use the hell out of this thing, it’s too foreign to Marine marksmanship culture, which is a master-and-apprentice culture that demands effort, even hardship, and eschews automation or corner-cutting of any kind. So we’d put these excellent Marine precision marksmen way down the list, right now. We’ve worked with enough 8541s to know that they like to do things the hard way, and they take particular joy in doing it the hard way faster than an Army guy can do it the easy way, and take a positively indecent glee in breaking the dogface’s easy-way technology. Bringing this to the Marines first means that they will use their considerable intellect and energy to break your machine and send you away with a duffel bag of expensive pieces (so they’re great for finding unimagined points of failure — there is that). Bringing it to them after selling it to the Army is not a panacea. It might be even harder, because they will be energized to demonstrate that the Army did Something Stupid, because if Marines believe three things about the Army it’s that: we have too much money, too little guts, and way too little brains.

You’ll probably need a Marine sniper on board to sell to Marine snipers. Once you do, you won’t get quite the global reach that you do by selling to SAS or its American counterparts. But you get in with the world’s greatest military image machine, and there is that. 

You have to be very careful about selling in to Hollywood. (One TrackingPoint precision guided rifle is already in the hands of the most successful firm that supplies movie and TV weapons and armorers). The reason is that an inept display of your product can hurt sales. (It would be very Hollywood to put the TrackingPoint system in the hands of a villain, to be overcome by someone like a Marine sniper or James Bond willing to use superior skill and old school firearms).

What’s Missing From 1st-Gen Tracking Point

While the extant system has undeniable SOF applications, it also has limits, and some technical improvements — none of which are impossible or require TrackingPoint engineers to schedule an invention — would increase its marketability in military precision riflery circles.

Emission Control / Encryption / ECCM

It’s great that you have a computer in a scope, and it’s the wave of the future. But the computer can be located by enemy SIGINT. The video and wifi links need strong encryption, and in addition they need to be controllable so that emissions can be closed down. Even third world enemies often use electronic support measures these days, and so you need some RF low-observability measures, and you also need to have electronic counter countermeasures to ensure usability of the system in an electronic environment.

Two-way communications

This one engenders some risk, but there should be a capability for the opetator to hand off control of the PGM’s optoelectronic systems to someone’s telepresence from a support station. Or even from another field station.

Intelligence gathering MASINT capability

There is everything in this weapons system that’s needed, for instance, to remotely measure a prison camp or a suspected SS-20 missile TEL. This capability would also tie in beautifully with the improved communications and encryption capabilities mentioned above.

A Ballistic Development Interface, SDK or App

Now that we have that in-scope computer, fully integrated with the hardware of the firearm, we need to have a way to make it more adaptable to different ammunition loadings, including one-time, single-mission loads. And that has to be done at the unit level; otherwise you’ve got a potential breach of compartmentation.


This is a sales stopper with top tier units. They develop their own long range capabilities, including, at times, loads, and they do it because they think they, like benchrest shooters, can handload a more consistent, higher-precision round than even premium ammo suppliers can do.

Demonstrated, Documented Durability

The running joke is that a soldier or marine can break a ball from a ball-bearing — just leave him alone in a room with it, and you’re a half hour from looking at a broken ball, and hearing, “Uh, I dunno, sarge. It just broke!” (Bearing-ball, hell, these guys could do that with a wrecking ball). You want your machine to be wrecking-ball strong.

Demonstrated “Fail Safe” mode.

The capability of the system has to degrade gracefully. If you’re sneakin and peekin’ on Day 38 of a “14-day mission,” dead batteries can’t leave you in shoot-randomly mode (let alone, can’t-shoot mode). Even an ACOG, which is probably harder to break than the gun it’s atop, has cast-in backup sights. But with a TrackingPoint gun’s scope being dependent on a CCD display at the shooter end, you can’t afford to have dead batteries.

Full Auto Stabilization Mode

We can’t be the only ones who looked at this and thought, “tag, track & x-act really could up the game of a door gunner and/or Boat Guy.” Hell, those Chenoweth sandrails might come back from the dead, if the gunners in them could actually hit things instead of just contribute morale-raising decibels to a fight. Imagine this Hollywood concoction, except real, and with the boost in hit probability than TrackingPoint promises.

You know you want one (more on the movie gun soon).

Note that these are just for the military employment of tracking point, as combat weapons technology. We haven’t even addressed the utility of tracking point for big game hunting, which is what the thing was developed for in the first place. Its applications for everything from African plains game to heliborne predator control seem self-evident. We haven’t even hinted at the potential for a rimfire TrackingPoint squirrel slaughter system, something that would sell itself once the price comes down.

As we all know, the guys running TrackingPoint are not stupid. They are probably thinking of most if not all of these things already. If not, hey, our rates are reasonable; drop us a line.

Wednesday Weapons Website of the Week: Tubalcain’s Machine Shop Tips

If you want to work on guns, you have to be able to work metal. Fortunately, metalworking is not brain surgery. Unfortunately, it is very complex and requires hands-on experience to develop any kind of skill whatsoever. So it’s good to have guides to the terra incognita of metal work, whether it’s something as simple (or is it?) as metals recognition, or as complex as making, installing and setting up repair parts for a broken lathe.

At one time, the only way you could get help gaining the experience to work metal was by apprenticing yourself to a master, or taking years of shop classes. But that was then, and now there’s YouTube, home of all kinds of how-to videos (some of them by Bubba or at least his mentors). But many of the instructional videos are of high quality. We’d like to single out “Tubalcain’s” series of videos as particularly useful to the beginner or learning machinist or metal worker.

We first found his videos when getting the hang of foundry, but this week discovered that someone had organized them all on a web page.

This extensive list of “Tubalcain” YouTube videos was sent by mrpete222.  To access them go to his YT channel and scan down the list.

The name “Tubalcain” is a Biblical reference, and an apt one.

From Wikipedia:

“Genesis 4:22 says that Tubal-cain was the “forger of all instruments of bronze and iron” or an “instructer of every artificer in brass and iron” . Although this may mean he was a metalsmith, a comparison with verses 20 and 21 suggests that he may have been the very first artificer in brass and iron. T. C. Mitchell suggests that he “discovered the possibilities of cold forging native copper and meteoric iron.” Tubal-cain has even been described as the first chemist”


This is definitely a page you’ll want to come back to. It’s edifying just to have one of these videos playing on another monitor while working — or we think it is. Hell, we may even learn something.


A 3D Lower we Missed: Vz61 Škorpion

Here’s one we missed in this morning’s roundup: Czech Vz.61 Škorpion. Less than a minute of 3D revolution for you:

The Škorpion (the symbol on the “Š” makes it an “Sh” sound, so it sounds like “Shkorpion” in its native tongue) was a personal defense weapon designed by CZ, then a “Narodni Podnik” or “National Enterprise” in the former Czechoslovak Socialist Republic in 1958-59 and adopted in 1961. (The Vz. stands for “vzor,” meaning “model.” Silly Czechs, they have a different word for everything!)

There’s a great deal of noise about the Škorpion having been designed for Czechoslovak special operations forces or espionage agents, which can best be classified as bullshit. The weapon was for officers, radio operators, support troops and others whose primary mission reduced both their requirement for and ability to carry a regular sized rifle. In other words, it was a conceptual successor to the M1/M2 carbine; the Poles developed a weapon that fit this same niche at about this same time.

At the same time as the Škorpion’s development, the Czechoslovak military was converting from a traditional semi-auto battle rifle in intermediate cartridges, the Vz. 52 and Vz.52/57, to a modern assault rifle in an intermediate cartridge. (The Czechoslovak engineers developed a short-lived 7.62 x 45mm cartridge, which was replaced by the Warsaw Pact standard 7.62 x 39 for interoperability’s sake). The Vz. 58 assault rifle that came out of these efforts resembles an AK in profile, but is a completely different weapon, with different magazines, operating system and manual of arms.

The folding-stock variant of the Vz. 58  is reasonably compact and eliminates some of the justification for the Škorp. So it gradually became sidelined in Czechoslovak forces; many years later, after the fall of Communism and the peaceful and orderly separation of the Czech Republic and Slovakia into separate states, most of the Škorpions were removed from service and sold; many of them wound up in the USA as parts kits, and more were rebuilt as semiautos with new lower receivers and other modifications. The semi Škorps are available on the market as pistols, or as Short Barreled Rifles under the provisions of the National Firearms Act.

Returning to the printed lower for this gun, the usual plastics from low-end printers using the fused filament fabrication (FFF) process, ABS and PLA, are unlikely to be durable enough in the long term. Of course, the .stl files can be used to print many more types of material also, or to operate subtractive machinery like a CNC mill. And more durable plastics, such as Nylon 618, are already available; a $6k carbon-fiber printer is on the market, and carbon-fiber-reinforced filament for lower-cost printers is also on the way.

Exercise caution before printing the file and assembling a parts kit on to it, as you run the risk of violating several paragraphs of 18 USC §922. To make a legal SBR, it must be registered in advance on a Form 1. To make a legal semi, it must not accept full-auto parts that would make a conversion possible, and must fire from a closed bolt. To make a legal machine gun, you must have a manufacturer’s license and a demo letter, and have an approved Form 1 in advance. We don’t know how the video maker handled the legalities. Bear in mind the ATF is watching this area closely and, as an institution, prefers to pursue licensing or other paperwork violations, which are slam-dunk easy-to-prove felonies, over cases against violent criminal organizations, which may require long investigation and expensive, risky techniques.

The Latest in 3D Printed Gun Developments

As we predicted, last time we looked at this, 3D printing is evolving to better adapt the available materials in consumer printers to the requirements of firearms applications. No more is it true that a printed receiver, even printed of low-end materials like PLA on a low-end consumer printer, is destined for a short and unreliable life. And people are taking printing in new directions.

The Continued Evolution of the Printed AR Receiver

The first printed AR receivers were clones of their aluminum forebears. And they broke. Boy howdy, they broke. You may recall that between the M16A1 and M16A2, even the forged 7075-T6 aluminum receiver was redesigned for greater strength. Material, and strength, was added to the pivot pin supports into the buffer tower area, which are the most vulnerable areas of any A. receiver

Let’s start here:

3d printed disaster-no

That looks like what 3-D printer enthusiasts call a “rage print.” Printer rage occurs when something goes wrong in the 3D programming, and instead of making a nice, neat, three-dimensional part, your printer prints a bunch of gooey plastic strings going in random directions. That’s exactly what this looks like. But that’s not what this is. It’s actually a new support-layout software that allows saving filament (even though the most common filament, PLA, is a 100% recyclable thermoplastic). We think it’s Autodesk MeshMixer. The supports look like a thready mesh, but there’s an AR lower under there.

If you look at the lower closely, you’ll see that it differs in detail from a metallic lower, whether it’s the stock 7075 forging or the too-cool case-hardened billet that Trumbull uses for its work-of-art ARs. It’s much thicker in places, which helps to make up for the lower strength of the soft plastic. We mentioned earlier that this was inevitable; just as designs and evolved to take advantage of new materials before, we have to expect designs to evolve to take advantage of these new materials, and new ways of manufacturing parts with them. This model, the Hermes, includes an integral buffer tube and stock, making the weakest part of the AR lower (the buffer tower-buffer tube interface) a single part:


Here’s a couple more-evolved minimalist AR lowers, the Phobos (yellow) and Vanguard (red):



Vanguard and Phobos lowers

Simplifying the lower reduces its print time and its likelihood of print errors. Thickening its parts reinforces weak areas and eliminates stress risers. Note that these are “as printed” without extensive acetone smoothing.

Here’s the Phobos, with its minimal magazine tower, built into a firearm.

Phobos printed on DaVinci01


It is optimized for the C-Products Beta magazine.

Phobos works with c-products betamag


Here is a close-up. The increased thickness, for strength and durability, is clear. So is the rough surface finish. This example was printed on a DaVinci printer, an inexpensive printer ($500) from

Phobos note thickness and finish

Here is the Phobos on range test. 100 rounds so far, successfully, as of 10 October 14.

Phobos in action

Are they militarily useful yet? Not really. Only as a prototyping technology, but it’s already been used that way. For instance, when Taiwan developed a new buttstock for its service rifle, they used 3D printing to produce ergonomic test samples.

But one can’t help but be reminded of Franklin’s retort to a woman who questioned his interest in the Montgolfiers’ pioneering balloon ascents: “What use is it? Madam, what use is a newborn baby?”

Revolver Developments

It’s not our cup of tea, really, but there’s quite a few people working on mechanically operated revolvers. Some of these look like the ancient Mauser zigzag revolver; others look more like something that would come with a Nerf trademark on it. Some seem to resemble both:

Imura revolver rendering

That’s the Imura revolver, named for Japanese 3D firearm experimenter (and criminal suspect, thanks to that) Yoshitomo Imura.

The Regulatory Angle

Of course not everybody thinks additive Manufacturing applied to firearms is a good idea. Indeed number everyone thinks that manufacturing firearms is a good idea most of your familiar with California Democrat Mike Honda’s bill to criminalize all home gunsmithing. The bill is certainly DOA in Congress in an Election Year, when even liberal pols are willing to denying Mike Bloomberg three times, like Peter.

Meanwhile, police and regulatory agencies in the US, Britain and Australia have been willing to lie about the technology to spread FUD. Here’s a line from an article at

Although police forces from around the world are warning technology enthusiasts not to attempt to use 3D printers to make plastic guns, because each time they have been tested the weapons have exploded.

Of course they have, because the cops/authorities have lightened the infill to make grenades, not pistols. If you hollow out a 1911 barrel, it’ll blow up, too. That’s far from the only mistake in the article, which claims to be an overview and timeline of 3DP weapons. For example, there’s this pseudo-engineering mumbo-jumbo:

 Two factors in engineering still need to be overcome, these are; high stress resistance materials that resist knife edge loads and high temperature flashes.

Huh? “Knife-edge loads?” Somebody’s having hot flashes, and it’s not the guns. If you look back up at the start of this post, you’ll see how the AR receiver has evolved to be something effective that can be made of low-tensile-strength polymers. And then there’s  this howler:

Solid Concepts… [used] a direct metal laser sintering printer to create a replica of a 1911 Browning .45 pistol. To date this weapon has fired over 600 shots successfully. … printing such a gun to resell is not currently economically feasible.

Except, of course, that Solid Concepts is already printing, and selling, them. Which they do sort-of note in the article, in the bit in the ellipses.

Not everything in the article appears to be nonsense, but in particular, the idea that printed guns are proven to explode needs to be stepped on. Hard. Sabotaged guns are proven to explode: not the same thing.

And to Make Regulators’ Heads Go High-Order Again…

It’s bad enough, from the standpoint of a domineering regulator, that people are using technology to make firearms without a “Mother, may I?” from On High. But it’s gone beyond that. Japanese technologist Yoshitomo Imura has taken the whole thing in a meta direction by designing printable technology for making guns. His current designs include a 3D printer (not that that’s anything new; many printers are capable of printing their own parts) and, more remarkably, a 3D printed micro milling machine.


Certainly there are valid objections: the technology is not there to print a sufficiently rigid mill, the unit can’t match the rigidity of even a low-budget Chinese unit, etc., etc.

To which we say, “What use is a newborn baby?”

In a world where the products, the tools, and even the tools that make the tools are all fundamentally digital, banning guns isn’t just difficult. It’s impossible. Any attempt at “control” will be reminiscent of the manner in which the USSR and its slave satellites struggled, never succeeding, in mighty efforts to ban information – until they ultimately collapsedWhen banning books didn’t work for them, they tried banning typewriters. Certainly the Mike Hondas of the world will go after the digital information needed to print gun parts, but information continues its trendline towards greater freedom and independence.

What’s this 1911-based frame… whatchamacallit?

Every once in a while, something comes along that does a pretty good Stump the Monkey on is. This is one of those. Collector/Dealer Bob Adams thinks it might have been some kind of a test fixture.

Unknown device or test fixture possibly made from a ca. 1918 Colt 1911 frame. Fitted with what appears to be a large threaded ring. Equipped with two vertical uprights at the top of the ring and a hole on the left side. The grip safety has been replaced with a solid backstrap/mainspring housing. The non-functional half slide is not original to the device. There is no longer any provision for a breech locking mechanism, nor any way to secure a slide on the rails, so it could not function as a firearm. This appears to have been an unfinished or scrap frame extensively remanufactured into some unknown device or test fixture and is not a firearm. It may have been a fixture for testing hammer fall impact, or firing pin spring strength, firing pin protusion, or ???? Any ideas?

1911 whatsit 01

via Adams Guns.

We’re not so sure about that. It looks to us like those big threads were meant to receive a big barrel, and the two blocks — rear sights? suggest it might have been a long barrel. We also note the one piece backstrap (replacing the stock 1911’s mainspring housing and grip safety) doesn’t fit entirely well:

1911 whatsit 02

Could those gaps have to do with a removable stock? Perhaps the gun was meant to have some sort of single-shot action and a Marble Game Getter style stock that clipped on here. But we think it is more likely to have been a firearm than a fixture. Bob disagrees.

What do you think?

Wednesday Weapons Website of the Week: Impro Guns

impro_gunsAnother title for this blog might be, “Bubba the Gunsmith’s Wide World of Wonder.” But they call it “Impro Guns” and its URL is This little information about who makes the blog, or why, but it features the improvised firearms often seen on The Firearms Blog.

The guns vary from crude zip guns that are arguably more hazardous to be behind than to be before, to rather sophisticated weapons that even feign manufacturer markings, serial numbers and even proof marks. They are made by tinkerers, criminals, terrorists and revolutionaries, mostly in places where governments take a totalitarian approach to firearms, but also in places where firearms are available, but criminals seek greater firepower than then can get over the counter.

There are artfully concealed guns, that look like cigarette cases or tire-pressure gages. There are even some guns captured in process, with drawings or process sheets, clandestine manufacture style:

improvised chinese guns process sheets

Impro Guns gathers all these without even falling back on the Khyber armorers in Darra Adam Khel.

A lot of them are blowback, pistol-caliber submachine guns. We’re reminded, again, of a prescient poster by Oleg Volk (that we can’t find, damn it) that showed something like a Sten and said something like, “If you ban guns, this is what crime guns start to look like.”


Folded Ammunition of the 1970s – It’s FABRL!

5.56 Folded DummyWhen you find one of these cartridges — like a black plastic commemorative one, made for a cartridge collectors’ club, now up for auction on GunBroker, or the blue dummy on the left — it just looks weird. Made in several calibers (at least 5.56, 7.62, and 30mm) and simplex (one bullet) and triplex (three) versions, it offered benefits from both the standpoint of internal ballistics (in theory, more complete combustion before projectile exits from the barrel) and packaging (a substantially shorter round, a big deal with aerial cannons and other on-board weapons), and potentially lighter weights.

Andrew J. Grandy, Circa 1975.

Andrew J. Grandy, circa 1970s.

The conceptual designer, Andrew J. Grandy, of Philadelphia suburb North Hills, obtained several patents on his technology: 3,857,339 of 31 Dec 74, which described both the rounds and a variety of belts, revolver chambers, and other feeding mechanisms for the unusual rounds; and several that appear very similar if not identical to to the 31 Dec 74 patent, including at least three from 24 Jun 74: 3,890,730,  3,890,732, and 3,890,878, plus 3,913,445 of 21 Oct 75. (There are other seemingly duplicative patents under Grandy’s name).

Grandy made quite a few other patent claims, either while employed at Frankford Arsenal or after he left and founded his own company, “GTG”. One of his more unusual claims was a pivoting/folding stock, illustrated on an M14, that folded up and over the receiver, with the belly of the skeletonized stock forming a carrying handle; another was a prestressed-metal-lined fiberglass barrel. It’s unknown if either of these inventions ever rose off the drawing board to be reduced to practice. Most of his patents grant free use to the Army, suggesting that his research remained Army-funded even after he left the staff.

As the design of the folded ammunition matured, the cases, originally problematic steel weldments, came to be made of a polymer, which offered the well-known weight advantages over a brass case, despite the folded ammunition’s more complex shapes. (This was a serendipitious benefit; the complex shape required the cases to be made by a process like injection molding; it was not a simple drawn cylinder that could be made of brass by 19th-Century processes).

But the benefits of the round were hard up against the costs they imposed on manufacture and functioning of the weapon, and the limitations of the materials. The manufacture problem relates to the odd shape of the chamber, the functioning issues (which were worked out) relate to the fact that an axisymmetric item of ammunition, a round that is indeed “round” in section, doesn’t have to go into the barrel in any orientation except point-forward; a folded round has only one right orientation, and the other 359º of the compass are wrong.

If the folded round itself wasn’t odd enough for you, Grandy came out of the SPIW and SALVO era and would design a triplex version that appears to have fired three bullets from three barrels, using a single combustion chamber. We know little about these rounds, but the ammo collector who is selling a few individual folded-ammo rounds has pictures of the triplexes, too. First, compared to a SPIW-era triplex tandem round:

Folded triplex ammo

And then, a whole line of colorful triplexes:

5.56 Folded Live ammo

We’d really like to know more about this. It looks like that sort of 1960s invention that was the Thing of the Future™ then, and still is today. “Dude, where’s my jetpack, and my triplex blaster?”

The cost problem is, as the auction hints, largely in the development of compatible firearms. We have nearly 200 years’ experience with fixed ammunition in an axial arrangement of round cross-section and cylindrical or polycylindrical form. That’s a lot of catching up to do.

Today, polymer cases are again drawing interest as a way to reduce ammunition size and weight without taking on the complexities of caseless ammunition. But today’s polymer cases are axisymmetric. If they’re folded, they’re symmetrically folded, with the combustion chamber around the projectile, giving some of Grandy’s promised benefits without some of the loading and ejection challenges.

The Achilles’s heel of polymer cases is and has always been obturation, or lack of it; militaries that can afford it continue to stay with brass cases for the safety, storage integrity, and increased barrel life it brings, compared to plastic and steel alternatives. Despite that, many engineers and designers think we may see effective synthetic cases of some type replacing brass sometime in this century, and if that happens, designers will be freed from the limitations of brass-drawing in cartridge (and firearm) design. So pay attention, as your teachers said; you may see this again.

FOLDED, U-SHAPED OR ENCAPSULATED AMMUNITION WAS ONE OF THE MOST INTERESTING EXPERIMENTAL PROGRAMS CONDUCTED DURING THE 1960s and 70s AT FRANKFORD ARSENAL. Invented by Andrew Grandy (seen below in this FA publicity photo) the concept provided a separate combustion chamber. This allowed gases only to be conveyed to the base of the projectile instead of the unburned powder and gases which are typical of the traditional “in line” cartridge design. The concept was tried in several calibers. Production and chambering problems for a nonsymmetrical case undermined the development. Mr. Grandy was a long time ICCA member. The ICCA – International Cartridge Collectors association was the prior name for the current IAA – International Ammunition Association. In 1984 he produced commemorative sets of his folded ammunition design for the ICCA. After retiring from Frankford Arsenal Mr. Grandy went into business for a short time as GTG Inc. to promote his designs. THIS AUCTION: This is a LIVE black plastic ball with .55 grain projectile and GTG headstamp. Includes a descriptive flyer which explains the concept and a CD copy of the original design report.

via 5.56(.223) EXPERIMENTAL FOLDED U-SHAPED AMMO-2 : Vintage Ammo at

In addition to that auction, the same retiring collector is auctioning one identical round, and numerous other ammunition collectors’ items in his full set of auctions. He is also auctioning these rounds at (We cite GunBroker a lot more than GunAuction out of force of habit, but we have nothing against GunAuction).

The feasibility of this folded ammunition in 5.56 mm was studied by Frankford Arsenal in the 1970s. The study was Document Number FA-TR-76061, available on DTIC as Document ADA039156.

The benefits the Frankford investigators, Reed Donnard, Richard Rhodes and Thomas Hennessy, saw in the ammunition included reduction of ammunition packing volume, length, and weight, and several benefits that flowed from that, including vehicle space utilization and reduced logistic costs. The abstract of their paper explains why:

Folded Ammunition is a unique concept in ammunition design that relocates the propellant charge from the conventional position behind and coaxial with the projectile to one beside the projectile. For a given energy output, conventional axially symmetric amiltlnLtlon cartridges do not provide the most efficient geometrical shape for a minimum system parametric profile (system length, weight and bulk). Reconfiguration of the cartridge using the Folded Ammunition approach makes possible now what had previously been unattainable in the way of weapon/ ammunition system optimization. This report describes the concept, outlines its advantages and presents the results of a short-term analytical and experimental program that successfully demonstrated the feasibility of Folded Ammunition.

Andrew Grandy, the inventor of the folded-ammunition concept, was credited for “concept description” in the study.

At first, the capsule/cartridge design was wide open, with many possibilities under consideration.

Folded ammo concepts

The final decision was to use an oval-section capsule with the projectile on one arm of a U and the powder container on the other. This experimental 30mm round illustrates the general arrangement, as does the blue dummy 5.56 at the head of the article.

30mm Folded Ammo Frankford Arsenal

This picture shows the packing volumetric efficiency advantage of the folded 5.56 over a conventional round with the same projectile (you will also note that the projo is a lot longer than the then-issue M193. This bullet is an experimental low-density bullet Frankford was experimenting with at the time).


They named the 5.56 round the FABRL (Frankford Arsenal – Ballistic Research Laboratory) 5.56. The report is interesting for, among other things, one of the earliest small arms uses of finite element analysis, something that even at a crude 2D level required a big mainframe computer in the 1970s.

The early experiments used test barrels in test fixtures, but they graduated to M16A1 and Belgian FAL rifles modified for the FABRL cartridge.  Unfortunately, because DTIC’s copies come from binary-pixel microfiche, the pictures of the firearms in the tech report are illegible .

Initially, they decided to use steel for the cartridge cases. This didn’t work out entirely well. And by the end of the testing they’d made a grim discovery: while they could make a 5.56 round that was essentially a clone of the then-issue M193, they couldn’t make one that was enormously better. They could make some marginal improvements in the parameters that folded ammunition promised in theory, but not significant ones; not improvements big enough to justify a huge changeover, even if engineers could be sure there were more performance improvements to come.

And by then, it was the late 1970s era of the Hollow Army, and there was no money for research. Frankford Arsenal itself would soon go the way of Harper’s Ferry and Springfield before it. Folded ammunition “coulda be a contenda” but wound up, instead, as a curiosity for ammo collectors and readers of

How’s that Ghost Gunner Selling?

Ghost Gunner promo picAs of this morning, of 410 pre-order units offered for sale since October 1, 372 have been sold. (NOTE UPDATE NUMBERS BEFORE GOING LIVE)

Pledge $1299

162 orders

Limited (38 left of 200)

via Ghost Gunner. That was at midnight. By 1100 EDT today (only 0900 in DD’s Texas home), 181 orders had been laid against of the third increment of 200 units, with only 19 left unspoken-for.

These are true orders, paid for with credit cards (already charged) or Bitcoin (fully transferred), not unenforceable pledges.

Raised by this initiative: $340,328 (that’s 10x $999, 200x $1199, and 162x $1299) UPDATE: $365,009 (that’s 10x $999, 200x $1199, and 1181x $1299. Let it never be said we don’t show our math).The price for a unit is expected to be around $1,500 when the pre-order is over and regular production is underway. If the batch sells out, which even at the declining sales rate could be within 24 hours, Defense Distributed’s take will be $389,690 — with zero  going to Kickstarter or Indiegogo fees, because those businesses are anti-2nd-Amendment and don’t want this business.

The first batch of 10 for $999 sold out before 0800 Central Time 1 Oct 14, launch day. Next batch of 200 x $1199 sold out 2 Oct — within 24 hours of launch, according to DefDist tweets. A third batch of 100 was then launched, sold out 4 Oct 14, and extended to at least another hundred units. (It seems likely that they will extend the pre-order again if the remaining units sell. But having to actually build and deliver these things has to be a little bit daunting).

Tentative conclusion: Americans want to build their own guns, and are willing to spend to do it. (Sadly, they may be more willing to spend than they are willing to learn. You’ve always been able to do what the GhostGunner comes configured to do, with a manual mill and a simple jig, or even with a drill press, if you’re willing to accept some reduction in quality. Some guys have done it with a Dremel tool, but they may be named Bubba).

Great Post: Do I Need A Gunsmith?

The Browning workshop, back in the day.

The Browning workshop, back in the day.

There’s a great post over at 10-8 Performance’s blog,, that ties into some of the things we’ve been discussing. Specifically, how do you answer the question “Do I need a gunsmith?” We answer it a little differently from the way their blogger, Hilton Yam, does, but that’s because we have slightly different objectives than Hilton does. Anyway, we’ll concatenate the lede and close of his post:

One of the most common questions that is heard in relation to gun parts, and 1911 parts in particular, is “do I need a gunsmith to fit it?” The short answer – if you need to ask that question, you will have the best results if you have a gunsmith do it.

For example, it is easy to throw in a 1911 trigger and crank the overtravel screw around until the hammer drops. However, there is more to timing the trigger than that, and installation on a Colt Series 80 has even more issues that are not obvious thanks to the firing pin safety.If you expect to gain enough knowledge from just watching a couple Youtube videos, you are setting yourself up for eventual failure.

If you want to do it right and actually learn how to do the work, expect that the guinea pig gun is to be relegated to shop experiments and range work, and spend time researching the topics through multiple sources. If you just want to get to the shooting and not deal with becoming your own gunsmith, send your 1911 and the bag of new parts off to a qualified 1911 expert.

We do recommend that you Read The Whole Thing™ at Modern Service Weapons.

Hilton also says:

On the 1911, just about every single component could require fitting or turn out not fitting correctly. The grip safety, thumb safety, and the trigger components (sear, hammer, disconnector, leaf spring) are no place to assume that something will just drop in.

That’s not just the 1911. Yes, you can pretty much just shake a bag of GI parts and what shakes out will be a working 1911, but Hilton’s not talking about a rattly, very-reliable-with-230grain-ball-but-not-very-accurate GI sidearm; the name of his blog is Modern Service Weapons, after all. But the AR is the same way. If the parts you have are surplus mil-spec parts, you can pretty much shake them together and have a working gun.

But Parts is not Just Parts

You see, a lot of surp parts are actually surplus because they were rejected by company or Army inspectors, and a lot of parts that look like surp parts were made by Uncle Bubba’s Metal Injection Molding Sweat Shop or were investment cast from no-pedigree metal or sintered from powdered pot metal. Sure, Colt and FN and their subs do use those processes, but only after engineering analysis by real MEs and materials and process engineers. And when they do work up a new process, they use a very narrowly defined version of it, with a defined process sheet, and all parameters recorded and every batch subject to statistical quality control. (If the sample fails, the whole batch fails and is scrapped — or sold to less scrupulous manufacturers, or direct into the aftermarket).

Assembling a lower receiver is not rocket surgery, as we've said before. But low-quality parts can frustrate a beginner.

Assembling a lower receiver is not rocket surgery, as we’ve said before. But low-quality parts can frustrate a beginner.

That’s why you can buy an AR-15 lower receiver parts kit for $50-60 right now, but the “same” kit from an authorized Colt parts dealer will set you back nearly two hunge. The market knows, at some level, that the authorized Colt parts come with a small-g guarantee that they’ve been subject to greater care in processing than your kit from DPMS, BCM, or “no-name-whatsoever.”

The Army can document (or retrieve a document from their contractors to prove) what pour batch of steel went into the bolt head in a particular serial number of M4 (and they’ve actually done this in Article 15-6 and safety investigations from time to time). If you’re not the COTR on that contract, you probably can’t ever find that kind of thing out. If the part is made to spec, or even pretty close to spec, you’re probably okay, but you have no way to prove it. “Way to prove it” is why the bolt that holds the wing strut on a little Cessna is thirty times more expensive than the “same” bolt from McMaster-Carr or MSC Direct. The bolt is cheap, it’s the pedigree you pay for.

But What About Hilton’s Original Question?

Returning from the above 40 days and nights wandering in the Desert of Digression, where we depart from Hilton is on how to answer the question. He uses your self-confidence as a proxy for your competence. Frankly, if you are sure you can work on your gun it could mean that you’re an ace ‘smith, or it could mean that you’re an overconfident novice, “Unskilled and Unaware of it” as the Dunning-Kruger paper1 put it. You don’t know what you don’t know, and so self-instruction needs to begin with non-destructive processes on expendable parts.

His advice to practice on something other than a carry or home-defense gun, one that absolutely, positively has to go “bang” every time you bump the bang button, is excellent advice. There’s no substitute for classroom instruction and hands-on bench time or apprenticeship, but that’s not available to everybody, and you’re never going to learn if you don’t start doing. (That’s where the Gunsmith Specials in GunBroker come in handy. “Oh noes! I screwed up the muzzle crowning on a $15 .22″ are words you will never say).

Let Us Reiterate the Commandments (and add a Corollary to one)

If you want to learn gunsmithing, go for it, but remember the Commandments:

  1. A reproduction of Browning's workshop in the Browning Museum in Ogden, UT.

    A reproduction of Browning’s workshop in the Browning Museum in Ogden, UT. John M. Browning was an apprentice once, just like you. Of course, he was six or eight years old, so you have some catching up to do.

    Don’t be Bubba.

  2. Be conscious of your limitations. If you don’t know where they are on a task, you might already be beyond them!
  3. If you can’t change a light bulb, a mower blade, a set of spark plugs, and a dead-bolt lock in your home door, you need to up your general handiness.
  4. Troubleshooting is a science as much as an art. There’s a whole separate set of rules for troubleshooting. If you can systematically troubleshoot a car, an airplane, or the Xerox machine in the Sales department you actually already have a transferable skill.
  5. Only stretch one skill at a time. Don’t tackle a project that requires you to learn several new things at once.
  6. Never experiment on anything you can’t screw up. Put another way, never point your nascent skills at anything you’re not prepared to destroy. (See what we did there?) (Corollary: Experiment on the cheaper of two parts, when you have a choice — hat tip Dyspeptic Gunsmith).
  7. You can only get experience from experience. (“Good judgment comes from experience. Experience comes from bad judgment.”) You can’t get experience from YouTube or from AGI’s gunsmithing videopalooza.
  8. Small things first. Master armorer skills before you cut metal (or polymer). Swapping parts needs to be second nature.
  9. Toolmaking and heat treating are a key ingredient in gunsmithing.
  10. Don’t be Bubba.

ModernServiceWeapons is a great blog. We know one serious, focused, training-happy special agent who practically makes it his home page, and it’s easy to see why. If it’s never been our W4 here2, it’s a terrible oversight on our part, because they manage to combine succinct write-ups on gear with the sort of common sense that we’ve always wished was more common on the net in general and in gun blogs in particular.



1. Kruger, Justin, & Dunning, David. Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Leed to Inflated Self-Assessments. American Psychological Association: J. of Personality and Social Psychology. 1999 Vol. 77, No. 6.
2. It was. It was a Wednesday Weapons Website of the Week in November, 2012.