Category Archives: GunTech

More on the Czech/German AT Rifle

Our recent auction post reminds us that (1) we have to come up with some better way of flagging more interesting auctions and (2), and more to the point of this post, that there’s a lot of interest and misconceptions about the Czech-German AT rifle featured at one upcoming auction.

First, this 2015 post here has some background on rifle-caliber-yuuuge-case AT rifles, like the German and Polish variants, and their rounds. (This archived external page also covers the round). The Germans chambered this rifle in their standard wartime 7.92 x 94 mm P318 round, which was used in the standard German PzB 38 and 39 AT rifles. The round was capable of 4,000-plus fps from a long barrel and the most common ammo was a tungsten-cored kinetic penetrator. P.O. Ackley, eat your heart out. Barrel life was pretty short, but if you’re going to shoot a rifle at tanks, it’s not the life of the barrel that should be worrying you.

(The Russian site that cartridge picture is from appears to be down now, unfortunately).

Those rifles operated by a dropping block, like an artillery piece (or early breechloader), and their principal mechanical difference was that the PzB 39 was manually operated, replacing the “semi-automatic” (in artillery terms) automatic opening and ejecting of the PzB 38.

The Czech rifle used completely different principles, and as proposed for Czech service a different cartridge.

In fact, the Czechoslovak Army experimented with a variety of anti-tank rifles in the 1930s, as part of a campaign to improve AT defenses overall. Many Czechoslovak officers put their faith in conventional anti-tank artillery, but others pursued the AT rifle. Many versions were tested including Josef Koucky’s’ ZK 382, a bullpup repeater which fired a unique 7.92 x 145 mm round, further ZK single-shots ZK 395 (12 mm x ?) and ZK 405 (7.92 x ?), the ZK406 repeater and 407 self-loader the “Brno W,” the Janeček  9/7 and 15/11 mm Gerlach-principle squeeze bore, and several 15mm designs, including vz. 41 single shots, and a bolt-action magazine repeater which was supplied to Italy (in only 15 units) and possibly Croatia. The 15mm guns used an AP version of the 15 x 104 mm round used in the Czechoslovak vz. 60 heavy MG, produced primarily by the British under ZB license as the 15mm BESA. The Czech engineers then reworked into the vz 41 in 7.92 x 94 for the occupiers, specifically, for the SS.

During all this experimentation, Czechoslovakia was dismembered and its Czech provinces occupied. The best was the enemy of the good; nearly a decade of experimentation in AT rifles wound up yielding absolutely nothing for the Czechoslovak Army. (It was a moot point, perhaps, as despite its strengths in tanks and artillery, there was no resistance to the Nazi occupation.

Most of the elite of the Czech arms design industry worked on these rifles at one time or another. Vacláv and Emanuel Holek worked with Koucky at Zbrojovka Brno; Jiri Kyncl worked with Janeček.

By the time the SS received their rifles, they were already hopelessly outclassed by improved armor, and among Speer’s actions in his attempt to rationalize the chaos of the German and occupied territories’ arms industry was to discontinue production of the 7.92 x 94 Type 318 ammunition.

The M.PzB.SS.41 was supplied in a wooden transfer and storage crate containing the rifle, two spare barrels, and four magazine boxes containing five magazines each. There were some variations in minor features (bipod, muzzle brake) during production. Of some variants, only photographs or documents survive. We have found no reports of combat effectiveness.

All of these AT rifles are rare today, the German guns existing in single-digit quantities (the mass-produced PzB 39s were recalled during the war and converted to grenade launchers, the GrB 39).

Sources

  • Dolínek et al. Czech Firearms and Ammunition: History and Present. Prague: Radix, 1995.
  • Hoffschmidt, E.J. Know Your Anti-Tank Rifles.  Stamford, CT: Blacksmith Publishing, 1977. (A .pdf of the chapter of this out-of-print book on this rifle is attached: MPZB41 comp.pdf)
  • Šada, Dr. Col. Miroslav. Československé Ruční Palné Zbrane a Kulomety. Prague: Naše Vojsko, 2004. (pp. 139-142, 197-198).

Update

Well, this is embarrassing. Never hit “schedule” or “publish” on this one. -Nose

Update on Jeff Rodriguez’s Electrochemical Machining of Homemade Barrels

We’ve covered Jeff’s creative electrolytic barrel processes before, but here’s a new update from him, posted on 6 March 2017.

In addition to the YouTube series — this is Jeff’s 24th update video — he’s been getting a lot of demand for assistance and even for Electro-Chemical Machining (ECM) kits. He’s set up a website at liberator12k.com — right now, there’s nothing there but a page collecting email addresses for updates. We’re signed up…

Your Ghost Gunner Results: Good, Bad or Mixed?

The WeaponsMan Ghost Gunner, early in its testing, hogs one of the gunsmithing benches with a Mac and a PC (we were checking that a connection problem was not emulation-related. It wasn’t, it was a driver issue).

John Crump has an interview with Cody Wilson at AmmoLand.com. It brings us up to date, but if you’ve been following Wilson and Defense Distributed it doesn’t really break any new ground. But what interested us was the colloquy on the Ghost Gunner. In the interview, John said this about the CNC mill, a device we know and have used a little.

John Crump: Why did Defense Distributed decide to make the CNC machine, The Ghost Gunner (GG)?

Cody Wilson: We needed to make a product we could sell to raise the money to sue the State Department over Liberator. I’m being totally serious. GG came from ideas given to us through the course of Wiki Weapon and the success of DEFCAD. People often suggested we should make a CNC and stop being silly with the printables.

John Crump: The Ghost Gunner 2 is truly revolutionary. Why do you think the NSSF decided not to give membership to Defense Distributed which basically banned DD from shot show?

Come and Take It: by Cody Wilson
Come and Take It: by Cody Wilson

Cody Wilson: Honestly I think it’s the simple trouble of the association. We are suing the DDTC, a bureau in the State Department that enforces export controls and is a group the NSSF has to make very nice with so they can pretend to continue to influence policy directions. Nevermind that they have humiliated themselves with DDTC’s most recent guidance on gunsmithing, not to mention the outright disaster that the last six year of “export control reform” have been. Great work NSSF!

Cody Wilson is probably right about why NSSF wants to keep him at arm’s length: he has no interest in playing nice with others; his Spirit Diplomat is Gavrilo Princip.

But John Crump’s positive description of the GG produced this response in the comments to the article:

I bought and received a GG machine in March 2016. I read all the instructions several times and sent several emails with questions and then began to mill out a lower AR.

The machine milled it out well until about 5 minutes into the job and then the bit became stuck in the aluminum block and the milling program shut down after the bit broke free.

I contacted GG in Texas and I told them I do not understand why the machine did whet it did nor did I know how to correct the problem as I am {{{ NOT }}} a mechanical engineer nor am I a computer programmer . I told them I only have a 10th grade education and asked if the machine was idiot proof, they said it was….. I felt safe!

In Feb of this year, GG sent me a email telling me I had to order a new second generation spindle as the old part did not work very well (as I learned). It is now one year after I first received my GG machine. I still have 9 unmilled lowers and one damaged unfinished lower and a GG machine that is locked up and won’t work. Basically I have given up on it all!

A year has passed and I have not yet milled out my first lower AR15 lower! ……….. PERFECT!

We have to say that our experience with the GG was different than what Ben describes, too, but it was not without glitches. We have successfully milled out lowers with both the Windows and Mac versions of the software. We had some difficulty with setup, early on, and Defense Distributed’s Ben Denio was extremely helpful in getting things sorted out and in production.

We’ve also had one head-crash, trying to cheat a little and use a lower without a 100% milled out takedown pin pocket. In our case, the head crash did no permanent damage, but did cause an overload indicator to light up and we had to reset the whole machine (instructions are included in the manual, but they’re hardly crystal clear).

The manual is difficult to follow and we suspect that it would truly be a nightmare for a less computer-savvy person.

One final problem that we’ve had is that we get fine lines between each depth of the trigger pocket cut. We believe that that is due solely to our GG being on a wheeled cart, and moreover, set on a thin rubber mat on top. The axes of the machine move with considerable vigor, and it is not heavy enough to hold itself down. We suspect that these lines will resolve, giving us an appropriate surface finish, if we lock the GG down better.

File Photo of a GG.

The GG community, such as it is, really feels the lack of the forum originally envisioned for open-source solutions sharing. It didn’t happen, not by any fault of Cody’s, Ben’s, or anybody’s at Defense Distributed, but because the State Department took it in its Deep State head to ban anyone talking about making guns. (Rifle-caliber small arms need to come off ITAR, but that’s a whole other issue).

We seem to recall that several WeaponsMan readers have also bought a GhostGunner, and also have had mixed, but mostly positive, results with them. Perhaps we can share some solutions here, and troubleshoot the woes of Ben Miles and anyone else experiencing technical problems.

Future Firearms Prototyping Enabled by 3D Printing

We’ve been on to the 3D Printing thing for years now. In fact, we have mentioned it in a staggering 165 posts, going back five years. In a post on 8 March 2012, we wrote:

Several new manufacturing technologies are creating an “Army of Davids” effect on arms manufacture. These are partly driven by computing technology and Moore’s Law, which makes uneconomical manual process suddenly automated — computer controlled machining and manufacturing, and partly driven by materials and manufacturing technology advances, like high-strength composites and 3D printing.

These technologies have the potential for great societal and economic benefit, but at the cost of making governments lose control of arms and ammunition manufacture. As we’ve seen with drugs, failure of a prohibition policy seems to lead to wider and more annoying (to the non-criminal majority) prohibitions.

In addition, traditional manufacturing technology including casting and machining have become more available to the general public recently, due to increased performance, smaller size, and vastly lowered cost of the tools required.

The half-decade since has seen an increase in all these trends. For 3D printers, most of whom are restricted to low-strength plastics like ABS (styrene) and PLA, and the edge cases are 3D printing nylon with fiber reinforcement, being able to print metal has been the Holy Grail, a seemingly unattainable, but highly desirable, object. Our own blog has contained the words “3D” “print” and “metal” in 52 posts in that same period, almost a third of all 3DP references.

So where are we today, in the first quarter of 2017? We can report that the technology to print 3D metal directly and indirectly is still industrial-priced, but it remains the subject of much effort, and the industrial price is a fraction of what it was five years ago. In particular, we’ll look at three ways to print and produce metal parts — one we mentioned before which didn’t pan out, and two new ones, one which has been commercialized and one which is freshly invented.

Sinterhard Filament: Failed Kickstarter.

You can’t win them all, but this was a big disappointment. The idea was simple: new filaments would contain a plastic binding agent as a substrate, and carry a payload of powder metal. The plastic could then be burned out and the net-shape powder metal part sintered to solidity in an industrial oven, Unfortunately, the project appears to have failed.

The sintering part of the process was never in doubt; it’s been used for automotive and firearms parts for a very long time. But if you can’t feed the material to print the parts, you have to fall back on the sort of mold technology that sintering has long relied upon.

But there were technical problems. For example, loading enough metal into the plastic for the sintering to work had a tendency to make the plastic too brittle to be rolled onto a feeder spool. There were also issues with nozzle wear.

The technical problems may have been overcome. It was other business problems, including the anti-business stance of the local community (Sinterhard came from Massachusetts) that appear to have knocked Sinterhard off any probability of early success.

The principals do continue research, they say, but it’s hard to imagine this project succeeding.

MarkForged Metal X

We’ve been as remiss in writing about last year’s Mark X as we’ve been in using our original Mark One or upgrading it to the Mark Two. But if the nylon with fiber reinforcement (Kevlar, carbon fiber, fiberglass) of the earlier Marks was something, this year’s Mark X is the defense and aerospace prototyper’s dream machine (<2 min video):

It’s an industrial machine that has industrial costs (budget $100k) and requirements (480v three-phase power; a floor that will support a 2500 lb. machine). But it does produce metal parts… by a sintering process remarkably similar to what Sinterhard tried, and failed, to achieve. The MarkForged process, though, appears to be entirely encased in the machine — not requiring the separate 3D printing and part sintering workflows that Sinterhard envisioned.

The materials currently available and shipping are stainless steel 17-4 and 303; materials in beta test include 6061 and 7075 aluminum, titanium 6-4, and tool steels A2, D2 and M2, and for all you turbine and rocket designers out there, Inconel 625. (Make the GyroJet great again!)

MarkForged calls their process ADAM — Atomic Diffusion Additive Manufacturing.

Speed time from design to strong metal parts with this accessible and compact process. ADAM prints your part using a bound metal powder rod that transforms into a dense metal part in one easy step. Bulk sintering provides crystal growth through all axes giving your parts excellent mechanical properties in all directions.

ADAM also enables the creation of unique geometries such as closed-cell honeycomb infill. Parts can be printed like the structure of bones – a closed cell inner core encased in a solid outer shell. This geometry is not possible using traditional subtractive manufacturing processes or DMLS.

The brake handle above illustrates (top complete, bottom cutaway) this type of construction which is, as they say, not possible to make using milling or powder-based Laser Sintering processes.

Comprehensive information on the MarkForged website.

Vader Systems MagnetoJet Technology

Vader Systems is not named after the fictional character, but after the principals of the company, inventor Zachary Vader and his father Scott Vader. They have invented an entirely novel 3D metal process that is best suited (at present) for aluminum alloys and others that liquefy in a similar temperature range. A magnetic field is used to deposit droplets of the molten metal, where it bonds to the adjacent droplets to make a solid part.

Here’s the how it works:

And here’s an overview of the advantages of this system, with Zach and Scott explaining the particular advantages of their system over other metal additive technologies.

It can be fast: this video shows the manufacture of a small cylinder in real time (with, later, an inset of the droplet production shot with a high-speed camera). The part is only near net shape, but it’s sufficiently solid to be brought to final net shape with traditional subtractive methods. Of course, just as the resolution of inkjet 2-D printers improved rapidly, the same process is likely to take place with metal 3-D printing, bringing the manufactured part closer to the golden ideal of print-to-true-net-shape.

Vader is finalizing the design of a printer which is planned to ship in 2018  — it will not be consumer priced, though (probably $250,000), and is a forerunner for future systems that would use a gang or array of nozzles to produce much higher metal throughput.

Aurora Labs S-Titanium Pro

It’s only fair to mention that Australia’s Aurora Labs claims to be shipping their S-Titanium Pro, a multimode printer that sells for $50k (FOB Down Under, net of GST), runs on open-source software, and can reportedly use a wide range of powdered metals. The company website is a bit confusing but a .pdf brochure is somewhat clearer as to what Aurora offers.

Assault Rifle, Alpine Style, Clear as Ice Edition

Thanks to Chuck at GunLab for turning us on to this incredible post on the Swiss Rifles message board. As Chuck tells it, Dale got hold of, not a rare StG 57, but a rare2 cutaway version of the StG 57.

And then he posted a series of photos and a thoughtful analysis of this highly unusual rifle that replaced the Swiss Army’s rifles, light machine guns, and submachine guns at once. (Does that make it the Swiss Army Knife of rifles? Sorry, couldn’t resist.)

As Dale explains, there’s a lot that’s unique about the StG 57:

The Stgw 57 is an interesting battle rifle. The rationale behind this gun was to arm the infantry with an “universal weapon” that would replace the bolt-action rifle, machine gun and machine pistol. It was selected in late December 1956 over the Waffenfabrik Bern competitor for cost reasons (the SIG prototype costed only 495 CHF to produce over the 1100 CHF that the W+F Bern model required).

It was always expensive, and while a semi model sold in trickles in the USA, the high price and the rare (here) 7.5 mm caliber kept it from taking off. One of our team sergeants had one and it was a thing of rare beauty (we think he later traded it for an NFA registered 4.2″ mortar). A later export model was chambered for 7.62 mm NATO, but it didn’t sell any better.

It incorporates a modified roller-delayed blowback mechanism inspired by the StG45/Gerät 06 H prototypes, folding sights from the FG42, and a buttstock socket just like the famous MG42. In order to reduce production costs, SIG used innovative production techniques and rubber/polymer materials for the rifle’s construction, in an effort to minimise the number of machined parts.

The cutaway provides a rare chance to truly observe and understand this unusual weapon. The original post includes comprehensive photographs and explanations.

Of course, being a Swiss rifle, no compromises were made on the quality of the construction and overall robustness. Because of its heavy, welded, machined, stamped and brazed construction, the Stgw 57 weighs a whopping 6,5 kg fully loaded! Not only is the rifle one of the heaviest service weapon of the world, it is also one of the most expensive! Each Stgw 57 costs the Swiss government a grand total of 1000 CHF (of which 495 CHF are production costs and 75 CHF accessories).

In this post, we’ve placed a couple of selected images. But really, you must go there and Read The Whole Thing™; you’ll see many more images and each one has a deep technical description of what you’re seeing. Very highly recommended!

Update on the FK Brno 7.5

We have written about this pistol before, but it’s had a long and arduous trip to market, and it’s still not really here. It may finally be coming (and here’s another allegation of imminence from four months ago). In any event, we haven’t got hands on one yet — hell, we haven’t seen one for sale, but we’ve found a couple of articles by people who have handled the gun, not just the press releases. And of course, there’s the manufacturer’s website.

Despite the inventors’ denials, and the gun and ammo’s own unique technology, it clearly owes a great deal to the CZ 75 and its descendants. (That’s not a bad thing, necessarily. After all, everybody owes a great deal to the M1911 and its descendants, too). The lockwork seems similar to the precision-oriented CZ single-actions.

The pistol is manufactured conventionally, for a Czech firearm. That is to say its components are CNC milled from billet or from investment castings (possibly by Poldi, which has cast for ZB and CZ since CZ-Strakonice days, before CZ built the UB factory  in 1936).

Unique ghost ring FK sight.

But the FK Brno 7.5  offers a unique high-velocity round, a unique buffer system, and unique sights. The FK 7.5 pushes .30 caliber copper bullet at 2000 feet per second, not quite rifle speed, but better than such remarkable rounds as the long-defunct .357 Auto Mag. Its numbers make the .357 SIG look like it has the parking brake on.

 

It’s otherworldly enough to generate considerable skepticism. When the FK 7.5 first came up on the radar last year, John Zent of American Rifleman noted its sudden appearance on the market had a certain “out-of-nowhere” quality. John Roberts a Guns, Holsters, and Gear also was unimpressed by the claimed velocity, because it can be matched by a 9mm firing an ultralight 50 grain round — delivering half the FK 7.5s energy.

An FK 7.5 shortslide prototype photographed by Rob Pincus at the factory.

Here is celebrity trainer Rob Pincus, with what he promises is Part I of a multipart article. Rob was invited to the Czech Republic to try the gun during its long period in ATF purgatorio, and has some interesting comments.

A High Capacity Handgun that fires a propriety [sic] 100 grain round at over 2000fps and costs over $5000. The round, by the way, is still moving at 1500fps at 100 meters… which is the distance at which the pistol is zeroed with a unique set of sights when it comes from the factory. As others in the above links note, the gun is relatively large, fires a very powerful round and isn’t going to be cheap. FK BRNO also claims that the gun is very controllable and capable of high levels of precision. And, the only guns currently in the USA are there for government evaluation so that importation could be approved.

Per Pincus, the company considers itself primarily an ammunition research company, which builds the pistol as a way to get its ammo concept into shooters’ hands. He hits these takeaways — and elaborates on each, so you’ll want to Read The Whole Thing™:

  1. FK BRNO says that they are an Ammunition Company that also makes a handgun.
  2. FK BRNO set out to develop a handgun that delivered AK-47 performance in regard to Terminal Ballistics at ranges between 50 and 150 meters.
  3. The 7.5 round delivers high levels [of] precision.
  4. The Terminal Ballistics are even more impressive than the precision capability.

He concludes: “FK Brno have done what they set out to do.” We’ll say again, Read The Whole Thing™, and we’re looking forward to the next part.

The tactical niche this pistol fills is unclear, although it seems to overdo what the Secret Service and Federal Air Marshals Service selected the .357 SIG to do. It is, without doubt, a magnificent engineering accomplishment, and the prototypes seen so far are beautifully finished. One clue is that, in its native country, it is available in a folding shoulder-stocked version, making it a near-peer of PDWs like the HK MP7 and FN P90 / FiveSeVen combination. It also appeals to people who love that kind of engineering for its own sake.

If it’s a success, it will seem less strange in due course. If it’s not a success, it will be a footnote to firearms history of near-GyroJet proportions. Either way, we want one!

Name That Round!

Hey, don’t be surprised if it throws you. It sure threw us, and we thought we knew guns and ammo!

Need a hint? It’s .30 caliber, and a bit of a Frankenstein monster with a rebated rim and a sharp shoulder.

Need another? It was created as a deer-taking round, gerrymandered to fit a unique state law.

Give up? Explanation after the jump.

Continue reading

Let’s See Whitworths Shoot!

Last month we had a couple posts on the Sharpshooters of the Civil War, and on the Confederates’ unique Whitworth rifle.

Fred Ray, who’s written an excellent book on the Rebel Sharpshooters, sold us a copy of his book (highly recommended, and it’ll be in the next review roundup), and also linked us to a few videos of modern Whitworth shooters. Fred has forgotten more about this stuff than we’ve ever learned, so you can read what he writes with confidence.

Let’s take them in the inverse order from the way Fred posted them: hardest first. Here is a guy trying to hit a target at 1,300 yards with a Whitworth.

That kind of hit was credibly reported by both Rebel and Yankee observers of the Confederate marksmen. (The English Whitworth rifle was only used by the Confederates).

One of the real problems is seeing the target. While many of the wartime Whitworths were equipped with high-tech (for 1860!) Davidson telescopic sights… …this marksman is shooting over irons. One of the real problems at that range is seeing the target. Since more of you are familiar with more modern rifles, consider that the front sight post of an M16A1 rifle subtends just enough arc to match an E-type silhouette at 175 meters.

Another fact that should be evident is the sheer power of the Whitworth. Look at that thing kick! The recoil is visibly greater than that of an ordinary rifle-musket.

Reproduction Whitworths

The class of the repro field is the long-discontinued Parker-Hale, but they are few and far between. After Parker-Hale went the way of all flesh, there was a EurArms repro which used the Parker-Hale barrels with its own lock and stock. Here, Balázs Némeththe proprietor of CapAndBall.eu has gotten his hands on one of them, and not only fires it, but provides a good run down on its unique and remarkable technology.  “The Whitworth,” he notes, “pushed the limits of aimed fire out to 1½ miles.”

Pedersoli is making a new version of the Whitworth. It is available in Europe, but not exported to North America (yet, we hope). Here is his video rundown on the Pedersoli Whitworth. The Pedersoli has hexagonal rifling, but it’s cold hammer-forged. The rifle also has much simpler sights. He did not have a hex bullet mold, so used a .451″ cylindrical round, and still got quite good accuracy at 50 and 100 meters.

The finish on the Pedersoli rifle is, like many of their premium muzzle-loaders, very good.

His enthusiasm for these rifles, so far ahead of their peers that they seemed ahead of their time, is infectious.

Finally, here’s a special treat. It’s our friend from Cap and Ball again, but here he’s firing an original Civil War vintage American target rifle, of the sort that many sharpshooters mustered in with.

If you go to the Fred Ray post that we linked way, way up there, you’ll also see another one about the Civil War buck-and-ball cartridge — the only loading we’re aware of that has its own statue at Gettysburg. But that’s another story!

Homebuilt Innovation: Ultra Light .22 Bolt Repeater

This is a remarkable home made survival-type .22 rifle that is chock full of ingenuity.

It may be amateur made, but its builder, who posts on YouTube as ECCO Machine, has professional equipment, and, more importantly, skills. Most parts of the rifle are machined from billets of aluminum, titanium, and ABS plastic. The barrel is a carbon-fiber-wrapped .22 barrel liner. The bolt is made of machined titanium alloy with a welded-on handle, and it has a rare feature in a rimfire rifle, forward locking lugs.

The resulting rifle is ultralight: less that 1 lb. 3 oz. The featherweight rifle stows itself into a package less than a foot and a half long.

Unlike most amateur’s adherence to the material or materials, and process or processes that they know best, ECCO Machine’s practical use of a range of materials and methods is something worthy of a major manufacturer. Plastic, carbon fiber, aluminum, and titanium are all used in places where they’re most suitable.

The only steel or stainless-steel parts are the sear, striker, spring, screws, the barrel liner only, and a modified Savage stainless mag (with a really clever and dead-simple retaining catch that is its own spring).

The bolt’s forward locking lugs lock into a barrel extension, as in an AR; the barrel extension is also made of titanium. The rifle is readily taken down without tools. Everywhere the solutions chosen show both imagination and a practical turn of mind. For one thing, he came up with a really clever way to manage the cartridge feed by making the ejector do double duty.

There’s a really neat surprise in the grip (which he doesn’t count against the gun’s 18.9 oz weight) and the carbon-fiber stock can hold up to 40 .22 long rifle cartridges. There is a nifty titanium front sight base modeled on the classic AR FSB, and a special threaded muzzle cap that’s part of the rifle folding/stowage mechanism. (An alternate threaded adapter can convert these fine threads to the threads needed to attach a suppressor).

This video shows many more details of this intriguing firearm.

One of these should be built into ever ejection seat on every combat jet. Heck, we should build one into the RV-12.

There are several other interesting amateur builds on ECCO Machine’s YouTube channel. Hat tip, Hrachya at TFB.

ATF Cracks Down on Retro Builders using 80% Receivers

In an entirely unexpected turn of events, ATF has reclassified completed and even so-called “80% lowers” with a fake auto sear marking as machine guns, depending on who makes them. Here’s an image of one such receiver the Bureau has taken custody of and ordered destroyed.

The problem is that fake sear hole. Marking such a receiver with a small, engraved ring has been one detail adopted by detail-obsessed retro builders for years. The receiver above is a typical example of this detail obsession. It began as a so-called 80% blank, and has been completed to firearm stage. But it also has been engraved with Colt markings and extensively machined to change its profile from the current reinforced lower to the M16A1 vintage shape, especially in the vicinity of the pivot pin bosses and the buffer tower. Internally, the receiver remains AR-15 semi-auto profile only, and cannot accept M16 full-automatic parts.

High-pocket AR lower (l.) and M16 showing auto sear and more open receiver (r).

Under this novel, stretching interpretation, this 80% receiver blank, too, is probably a machine gun, even though it is not completed. No trigger group machining has been done, and it cannot accept machine gun (or any) trigger group parts.

There is no consistency to these rulings, and ATF lawyers insist that every ruling applies only to the single case at hand, which must be considered de novo, and that previous rulings are not precedent or even evidence. ATF lawyers will take you to court, and will fight to keep their own agency’s prior determinations out of that court.

The ATF has even given written approval to this engraving — when it’s done by large licensees who can afford lawyers to haggle over ATF rulings, like Colt and Troy:

(Troy has taken hits from the market before for hiring a disgraced ATF figure, and some infer an unusually cordial relationship with ATF management. The Troy receiver also has a couple of unique features, which are discussed below).

ATF has also approved the marking in the past, in letters to individuals and licensees, when it is out of position relative to the factory location of an auto sear. But the same engraving now, and done by or for a little guy who has no practical defense against an ATF attack? Strengstens verboten. 

When the definition of an object depends not on what it is, but on who you are, is it really law we’re talking about, or just power? Are we operating under a system of laws that claims derivation from the US Constitution, or under Hammurabi’s Code, which provided “different spanks for different ranks”?

This whole affair began during a routine inspection of US Anodizing in Virginia. All licensees accept such inspections, during which ATF inspectors or occasionally agents examine paperwork, inventory, and overall regulation compliance. Generally these are cordial and professional, but given the weak firearms knowledge of many ATF personnel, and its politics-first pursuit of gun control enthusiast personnel, sometimes they lead to disagreements or disputes. (And some licensees screw up; nothing thrills the ATF more than the chance to hammer a licensee, the bigger the better). On this particular inspection, there was no tension and no suggestion that US Anodizing was doing anything wrong, but ATF initially set several lowers in-process aside for further review. The inspector made a tentative determination that lowers completed from so-called 80% lowers, and showing any indication of a mock auto-sear pin anywhere on the side of the trigger group, was a “machine gun” because it would be “readily convertible.” That’s even in the case of a firearm that would require considerable internal machining to accept MG parts.

There were relatively few receivers — more than three but not more than six — with such a marking on site, but others may have passed through in the past, given this feature’s popularity with retro-heads.

The ATF actually hasn’t seized the receivers in legal terms. Instead, it is holding the receivers and has demanded that the owners voluntarily surrender them to be destroyed, or face prosecution. They say that this is a generous offer that they don’t have to make but are willing to do because they have determined that there was no intent to violate the law.

But, and here’s the rub, they’re demanding that the owners not only allow the ATF destroy the receivers, but also, that they sign a sort of Chinese-show-trial-confession letter, admitting having produced an “unregistered machine gun.”

UPDATE: The following was received from the owner of the 1st receiver illustrated above:

The 1st pic is of my receiver. I am one of the 6 or so that have had my receiver seized. I must tell you that this part :

But, and here’s the rub, they’re demanding that the owners not only allow the ATF destroy the receivers, but also, that they sign a sort of Chinese-show-trial-confession letter, admitting having produced an “unregistered machine gun.”

…is not true. I, at least , have only been given an ATF Form 3400.1. I have NOT been asked to sign anything admitting to creating anything or breaking any laws.

We stand corrected and have lined out the paragraph in question. Form 3400.1, Property Taken into Bureau Custody, is used in nonjudicial takings. It describes the property, and the person or entity from which the property was taken, but does not require or expect any admission of anything. This OIG report of some of ATF’s problems (.pdf) managing seized property in the 2004-05 period shines some light on the regulation in question, ATF 3400.1B. ATF takes approximately 200,000-300,000 items a year, of which about 10,000 to 30,000 have historically been firearms.

The owner of the receiver in the first illustration above decided to sign the ATF letter and let his “machine gun” be destroyed; others, who are not in the crosshairs of the ATF like he is, have criticized him for “caving,” but his choices are (1) give the ATF the Cardinal Mindszenty confession uncontested, nonjudicial surrender-of-property that they want, or (2) fight, with the possible outcomes of: (2a) a pyrrhic “victory” that would leave him a financial ruin after years of stress; or, (2b) a decade of two in Club Fed.

Of course, given the legal constraints and historically demonstrated character of the ATF as an institution, you can choose (1) and get (2a or 2b) also, if they feel like making an example of you.  Today. For something they approved for Harry yesterday and will approve for Tom tomorrow.

It is hard to fight this kind of creeping, arbitrary, whimsical regulation. Under most US regulatory law, the courts defer almost absolutely to the regulatory agency. As we understand it, and we’re not lawyers, court precedents rule that the expertise on any particular regulatory area is contained within the regulating agency.

There are social and organizational dynamics at work in the current regulatory environment. Once a field agent or inspector makes such a allegation, it’s the instinct of the Firearms Technology Branch to produce whatever it takes to support the ATF officer and keep him or her from losing face, even at the cost of the FTB’s and the Bureau’s reputation for consistency and even integrity.

ATF argues that Colt and Troy are doing something slightly different. For example, Troy’s receiver has a bridge between left and right sides, and is engraved REPLICA – SEMI ONLY for those law officers not steeped in firearms design and construction. But the real underlying problem is baked into regulatory law: there’s no reason that ATF can’t argue the law any of several different ways in different cases at the same time.

We see this ATF power grab casting a chill over the retro movement, which is a small and relatively inconsequential. But the bureau’s real target is the “80% lower” builder in general and the entire home gun building movement, which senior managers and the Chief Counsel’s Office would like to criminalize. This is one of the things that senior managers such as Thomas F. Brandon, who put the ATF behind the Hillary Clinton campaign in major newspapers, was hoping to get out of the Administration they wanted. (Wanted and expected. They had initiatives ready to go).

This is a legal minefield and anyone in this position needs a professional and experienced attorney (i.e. experienced with the ATF and with Federal gun laws).