Category Archives: Weapons Technology

What happens when a .50 fires out of battery?

This photo, from Armslist, appears to show the mishap firearm. Click for full-size.

The various .50 caliber rifle and machine gun cartridges are not trifles. One 18B of our acquaintance earned the nickname Nine Fingers in a moment’s carelessness with a loose round. (He’s not the only one. Here’s a gruesome weapons safety-of-use message from a couple of years later – via ENDO). You might expect that from a round that has 200 to nearly 300 grains of powder. With the .50 everything happens in greater volume and under greater pressure, which makes the quality of gun very, very important.

Mishap gun after the accident. Arrows show witness marks where the fast-moving bolt (r.) contacted the receiver and stock.

We’re about to see what happens when a .50 is not well engineered or constructed, and we’ll also cover ammunition as a possible contributing factor.

In recent years there has been a flowering of new .50 designs… 30 years ago it was Barrett or lump it. (That isn’t necessarily bad. The Barrett is a safe, sturdy, and reliable weapon). Now there are many kinds of .50s on the market. Along with the semis, there are bolt action mag-fed guns and a variety of single shots with nearly as many action designs as there are manufacturers. Some of the singles use a Mauser-like bolt with extractor and ejector, but others use a “shell holder” bolt, where a machined slot in the bolt holds the cartridge rim in place before, during and after firing, dispensing with the cost and complexity of an extractor or ejector. The price of this simplicity comes in the complexity of, and time to execute, the normal manual of arms. In a throwback to 1870s breechloader convenience, you remove the bolt from the weapon, slide any spent cartridge out of the shell holder, slide the cartridge into the shell holder in the bolt, and then ram the bolt/cartridge assembly home, turn it to lock, and fire.

That’s an inelegant design, but it’s perfectly safe, if the designers and manufacturers do their job of engineering, substantiation, and manufacture — and if users use good ammo.

Good ammo is hard to come by for .50s. Surplus blasting ammo is reliable and safe but generally falls short of the guns’ accuracy potential. It’s built for machine guns and meant to be fired at planes, vehicles, or groups of troops in a “to whom it may concern” manner. Match ammo, on the other hand, is usually reloaded, either by end users or small shops or companies. So one risk you take is with reloads, which even in a factory production setting do not get the statistical quality control that, say, ATK applies to their military contract rounds.

And then there’s the quality of gun. This gun is a Vulcan. Vulcan was formerly known as Hesse. Hesse made a series of very low-quality receivers for guns built on surplus parts kits — everything from FALs to ARs to 1919A4s. And every one of these was prone to failures, and the firm’s customer service — under whatever name — was dreadful. So then, Hesse (and later, Vulcan) got into .50 BMG rifles. Their guns sell for a low price point. Unfortunately, that encourages people who can’t operate Google or Bing to buy them. With the results you see here, and some results you don’t.

The Vulcan, also, has a chamber that, while it varies from gun to gun, is tighter than the military specification for machine-gun chambers. What this means is not all surplus ammo will chamber; max-milspec-length rounds may fail to chamber, like a no-go gage.

Vulcan and Hesse bolts, oldest to newest. Source: Outlaw Performance .50 Vulcan page. (Click for +)

The bolt in this particular gun is at least the fourth design of the the Vulcan/Hesse .50 bolt. The first one had two lugs, oriented at 90 and 270 to the side you slide the cartridge in the shell holder. The second had the same 2-lug bolt head and an improved rear area. The third, which was in early Vulcans, used an interrupted thread, but the fine thread doesn’t seem to have been sufficient for safety. The fourth and current bolt head has three lugs much like the ones from the early Hesse bolt, but arranged equidistant from one another (120 apart) around the bolt head. Vulcan says the bolt is machined from 4140 rod stock, but the surface finish of one we examined looked like a casting.

But the bolt itself didn’t let go. What appears to have happened in the latest case is that the gun fired out of battery. The firing pin free-floats in the bolt, and when the shooter rammed the bolt home, the pin’s own inertia was enough to fire the cartridge in the chamber, before the luckless shooter could turn the bolt and lock it. We haven’t seen even a picture of the inside of the mishap gun’s chamber, but we’ve seen other Hesses/Vulcans, and there’s a lot of tool marks and roughness in there.

In the current accident, the bolt firing out of battery exposed another limitation of the Hesse/Vulcan design (and all shell holders that we know of, really): there’s no secondary bolt retention. If the gun fires out of battery, the bolt is coming back with half the energy that propels the .50′s usual ~700-grain widow makers, and that’s exactly what happened here. The bolt struck and seriously injured the shooter. The blast, flash and burn from the uncontained powder and fragmented cartridge case also injured him; he was left blind and missing several fingers, although his blindness seems to be easing and they are cautiously optimistic he will recover his sight. Several fingers from his left hand were a different matter, as they couldn’t be found. (It is possible, but not known for a fact, that he was resting his left hand on top of the Vulcan’s stock, and the fast-moving bolt tore his fingers off on its way to breaking his shoulder).

Why did the gun fire out of battery in the first place? What none of the four bolt designs did include was one simple, five-cent component that would have prevented this accident: a firing-pin return spring. This spring is especially important if you’re going to fire ammunition that’s loaded with more-sensitive commercial primers than if you only plan to shoot surplus ammunition. Without one, it’s possible for the firing pin to jam in the forward position, like the fixed firing pin on an open-bolt submachine gun. Well, open-bolt subguns can be set up like that, because (1) they’re chambered for low-powered pistol cartridges, and (2) many of them are designed to use advanced primer ignition, where the gun fires as the bolt is closing. Again, no harm done in a gun that’s designed to be “locked” by the weight and inertia of the bolt. In a gun that absolutely, positively must be locked to fire, it’s a mortal error.

As veterans of Special Forces, still involved with the community today, we can assure you that this promotional claim is a great calumny. We never would use this garbage.

In the mishap Vulcan, the base of the .50 casing remains in the shell holder of the bolt. The rest of the casing became shrapnel, and the bolt itself became a deadly projectile. This man is extremely lucky to be alive, and he’s luckier yet if he recovers his vision.

Yes, a Barrett is four times or more what one of these things goes for, and even other single-shots like the McMillan cost much more money. What are your eyes worth? Your life? This guy very nearly answered that question, inadvertently.

Other Vulcan/Hesse .50s have blown up before, apparently. So have other makes of .50, but none of the top-name guns, as far as we know. This one at ENDO also looks like an out of battery fire, and seriously injured its shooter. It’s interesting because it was an AR-style single-shot bolt gun, that was not a shell holder design. On the other hand, it was made by an outfit we haven’t otherwise heard of, called “BOHICA Arms.” (BOHICA is an ancient military acronym for “bend over, here it comes again.” Not exactly a confidence-building company name. But hey, they’re not Vulcan/Hesse/Blackthorne).

Links

ARFCOM thread (as usual, a thin layer of genius floating on a lake of retardation).

Vulcan Armaments. The same Bubba the Gunsmiths that comprise Vulcan also appear to have operated as Hesse, Blackthorne, Frozen North, and probably other names. Name changes for the same reason that Chevy’s small shitbox car has a new name every few years: the public gets wise. Vulcan claims to be a supplier of guns to Special Forces. It is not. And you have to love their warranty policy: KMAGYOYO. (“Based on the Magnuson-Moss Warranty act, Vulcan Group Inc. offers no warranty on its product line.”)

Armslist ad with this rifle for sale in 2010.

Some more Liberator photos

3D Printed Gun: Mashable Mini-Documentary

Missed the DEFCAD files?

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There are places to go to get them.

Torrents work (the Pirate Bay, for instance) and are out of the reach of the US State Department, the IRS, and the various other agencies that are being used as hammers to drive political nails. If you know how to work BitTorrent files, you didn’t need us to tell you this.

They are easily found in the underweb. Google only takes you so far, but if you get off-google in the numeric realms (where we strongly advise you to only go with TOR or another anonymizing system), everything is available, including trouble. It’s the internet equivalent of the Mos Eisley cantina. On this subject: Michael Kassner at Tech Republic and Neal Ungerleider at Fast Company and again (differently edited version of same article) at NBC News. In addition to the Underweb, there’s the deep web or invisible web, and there are darknets. The first rule of darknets is… you do not talk about darknets.

The DEFCAD forums are still alive and people often point to file locations, which may be transient in nature. If you see it there and want it, hit it then.

A DEFCAD release clone is being maintained and updated by a fan here. This system’s got a learning curve if you want to do anything useful with it, but it’s comprehensive, complete, and free. Reading the Read Me file will make the learning curve easier to ascend (don’t ask how we know that).

As a tragic figure in a science-fiction movie said, “You can’t stop the signal.” That doesn’t stop certain characters from giving it their best shot.

Liberator-tje – Neutered Netherlands Liberator

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The Dutchman behind this project, Dave Borghuis, wants us to know he’s not a wacko bird like those “scary and crazy” US-ians.

I am not a gun nut, i find it scary things and crazy how the USA handle the gun laws.
Check your own local laws BEFORE printing any part of the Liberator-tje.

Just to make it clear that he’s an enlightened European from a nation that stood against the Nazi menace for over half a week (four days from invasion to capitulation in May 1940, followed instantly by more collaboration than resistance), he makes it clear that his Liberator is an enlightened, European, non-combatant Liberator.

In the Netherlands any gun is strictly forbidden unless you have a licence. To prevent any problems with dutch law I (zeno4ever/Dave Borghuis) modified the files so its impossible to shoot any bullet with the printed gun. I checked this with someone that has some insight in Dutch law regarding gun laws and the modifications I made should make it legal to print the gun in Netherlands. Be sure to check your own local laws if you want to print this Liberator-tje.

via Liberator-tje – TkkrLab.

In fact, his version is a cap gun. (That’s what the little ring in the top photo is — toy-gun caps, Euro style). But we’re probably being too hard on Dave. As he says elsewhere, he’s not interested in guns, he’s interested in printing 3D objects, and so he should be welcomed as another part and branch of the revolution. He did, indeed, print a locally adapted Liberator, even if it is a gelding, and he promises to make his revised (spayed and neutered) files available to the public, probably on his blog given the fact that the State Department has sent its Panzers to occupy DefCad for the time being. (Interesting if nonpertinent factoid: SecState John F. Kerry is, like the last Panzer-emitter, of Austrian descent).

After all, the Dutch may not have materially slowed the entire German war machine down, but one individual Dutchman fired a shot that took German paratroop general Kurt Student off the board for some very critical months of the war. A small nation in a tough continent has to live within the bounds of possibility.

Dave is also the first one we know of to have printed the Liberator on his particular machine, the common (well, to the extent any 3DP is common) RepRap Prusa i3. True, his is a cap gun, but it’s — you’ve been hearing these words from us a lot — a proof of concept.

Dave also made (we think; please correct us if we’re mistaken) this excellent animation of Liberator assembly. So we’re grateful for that, even if he thinks we’re “roondweg idioot” over here, which you can probably figure out even if you can’t grok Nederlands.

We’re also grateful to Dave for pointing us to this classically hand-wringing article by Cory Doctorow in the Grauniad. Doctorow argues that because Guns are Bad we need to find a way to ban 3D printing of them without, you know, banning 3D printing. It’s typical Doctorow, a tech lover losing out to his inner fascist, and as good an explanation as any as to why we haven’t been back to his site in about four years.

In the home-manufacture revolution, it’s From Each According to his Ability, and To Each According to his Liberties.

3D-Printed Guns: Lulzbot Liberator fires 9 shots

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A Liberator 3D printed handgun with several modifications has successfully fired nine shots from a single barrel. The shots were fired with a tether from a platform for safety.

This is the Liberator we previously showed you, printed on a Lulzbot, an under-$2k machine. This unit’s modifications from the original 3D-printed Liberator include:

Longer barrel
Rifled barrel (helps with regulatory compliance, avoiding NFA, but it’s doubtful that it imparts any stabilization to the round, for reasons we’ll soon see)
Screw instead of printed trigger and hammer pins
Different resin

Like Cody Wilson’s Prototype #1, this Liberator contains enough metal to comply with the so-called Undetectable Firearms Act.

Andy Greenberg of Forbes still seems to be torn three ways by his newsman instincts to cover this story, his techie instincts to applaud this, and his liberal instincts to condemn this technology. But his newsman side is winning and he continues to cover 3D gun developments in Forbes.

Meanwhile, the gun is discussed in this thread in the DEFCAD forums.

Takeaways:

Yeah, you can do this on a low-cost printer.
The generic ABS actually has better mechanical properties than the proprietary stuff Cody Wilson’s Stratasys requires.
Nobody has tested a .380 barrel to failure yet, so nobody knows where the failure point is. However, these guys were getting close. The headspace was increasing — and they think the bore diameter and chamber diameter were, too — with each shot.
The lack of rigidity of the barrel, compared to a steel barrel, takes a lot of velocity away from the .380 cartridge. They only captured 2 of the 8 shots’ velocity: 498.2 and 465.1 FPS. That’s half or less of typical .380 FMJ muzzle velocities, which range from around 900 to 1100 (per Ballistics 101). That would be a even larger proportional decrease in muzzle energy (because velocity is squared in the energy formula).

The best use for this, then, is as a technology demonstrator, and a proof of concept (as Wilson has consistently argued). But then, you couldn’t do much with the Wright Flyer either, yet there’d be no SR-71, Airbus 380 or UH-60 Black Hawk without the Wrights’ proof of concept and the other flimsy powered kites of wood and muslin that followed it into the air in the early years of the last century.

The Liberator also has a couple of other possible uses: a defense arm in places where people are so disarmed that even a marginal weapon like this is the best you can do. And there’s always the purpose of the original Liberator, as illustrated on its comic-strip instruction sheet: to whack some henchman of a tyrant, and take his factory-made gun.

That last use is probably keeping some wannabe henchmen up late at night. But if they were thinking henchmen, they’d be a lot more worried about the fact that it is the first raindrop of a deluge; or to put it another way, the Wright Flyer of a new technological era.

A Formation of Liberators

It seems like the verdict is in State Department’s attempt to do to DEFCAD what the DOJ is doing to the Associated (with terrorists!) Press and the IRS is doing to just about anybody who voices a word of criticism. And, while the East German judge gave the tactic an inexplicable 9, the Free World judges have some other things to say about USG’s attempt to stamp out 3D printing of gun parts.

Let’s start with a Liberator rendered on an older 3D Systems Cube, which is kind of like the Easy-Bake Oven of 3D printers.

Liberator printed on a 3D Systems Cube.

Liberator rendered on a Printrbot [stet]. Click any of the pictures to embiggen ‘em.

Then we’ll have a look at the way one comes out from a Printrbot. The Printrbot is even less expensive that the Cube, and doesn’t need high-$ proprietary feedstock, but it’s more complicated to set up. You can buy it as a complete printer or a kit, and there’s even a portable, battery-powered version. The smallest and simplest Printerbot kit (which you couldn’t build a Liberator on) sells for only $300.

Then, there’s the Lulzbot from Aleph Electronics. (Lulzbot? Who names these things, quasi-literate third graders?) The guy doing the Lib on the Lulzbot did his in a bright red plastic — perhaps for the Lulz. There are a number of different Lulzbots available, including some pretty high-end hardware for a hobby printer.

Liberator as rendered by a Lulzbot.

These “guns” were all in addition to the ones that Defense Distributed rendered on Stratays printers (over Stratasys’s objections and attempts to impeded and thwart their users), and in addition to the one rendered by some contractor for the chumps at the Daily Mail. (It’s a steady job, but they wanna be…). And these are only the ones already posted to the DEFCAD forums. There are more who are just making, and testing, but not boasting.

Before you do this thing, you need to familiarize yourself with the laws as well as the technology. (Technology, unlike the law, tends to get more user-friendly over time; so procrastination is your friend on the tech side. Law side, not so much).

Your gun needs to comply with the Undetectable Firearms Act (which means it needs to have 3.7 oz. metal in it) and it needs to be a Title I firearm, not a Title II weapon. If there is no rifling in the barrel, a handgun is a Title II Any Other Weapon (zip gun) and is subject to the National Firearms Act of 1934 — which requires you to get a license and a tax stamp before hitting “print” on your WhateverBot. The license requires, among other things, your fingerprints and the papal blessing of your local chief of police or sheriff; the tax stamp sets you back $200.

Some taxes are not really about raising money. (Economists call them Pigovian taxes, from one of their drear cohort who described them long ago, one Pigou).

About the technology: there are limits to the stress-bearing ability of printed plastics, and it’s considerably less than the same plastics, injection-molded (at least 20% less, for ABS). This is because the plastic is deposited in layers and is not homogeneous like injection-molded ABS would be. See, for example, the Liberator receiver close-up on the right (you can click to embiggen). You can see the layers (if you’re an engineer, you can see the stress risers!)

By the way: don’t tell Chuck Schumer or Steve Israel, but you can bypass most of the problems with a printed gun by printing it to common PLA plastic and then using the PLA part as a pattern for a mold. Add a couple of wax sprues and risers and embed the whole megillah in a plaster-sand mixture. You then melt the PLA out, and cast metal in. (Same as a jeweler’s lost-wax process, but on a necessarily larger scale). One of the real applications for these printers is in printing casting patterns (indeed, some are optimized to print wax — for just this reason).

Breaking: Defense Distributed Files Taken Down

Contraband… except it’s everywhere now. State Department, meet the Streisand Effect.

That didn’t take long.

Soon after Defense Distributed hosted the file for the “Liberator” 3D-printable pistol — a technology demonstration, more than a practical handgun, at this point — over 100,000 people downloaded the files.

Soon after that, the Administration ordered the files taken down, and threatened Cody Wilson with criminal charges.

While we’re tempted to fill this post with our opinon, we’ll serve up the raw information. Here are some relevant links:

A news story (don’t know this site) quoting wilson: http://redalertpolitics.com/2013/05/09/feds-force-defense-distributed-to-remove-3-d-gun-blueprints/
Anti-gun Andy Greenberg reacts at Forbes: http://www.forbes.com/sites/andygreenberg/2013/05/09/state-department-demands-takedown-of-3d-printable-gun-for-possible-export-control-violation/
A forum thread discussing the takedown, often updated with locations of files. http://defcad.org/forum/index.php?topic=866.0

Here is the letter Wilson received. Hat tip to a site we normally don’t visit, but CWCID, InfoWars. Greenberg’s link has the text of the same letter.

DEFCAD takedown (.pdf)

The man that signed the letter, Glenn E. Smith, is the chief of the Enforcement Division, which indicates that they’re not just interested in taking the files down, but that they’re going to push this as a criminal case, to make an example out of Cody Wilson. Wilson needs to lawyer up and not talk to this guy absent a lawyer’s advice — and at this point, he needs both federal criminal and export-control lawyers.

Smith is a type: a double-dipper who retired from the Navy in 1996 and reincarnated himself as a Beltway payroll patriot. He was at the same office as a detailee Naval Officer at the end of his Naval career — coincidentally, or not, when the office tried the same line of attack on encryption inventor Dr.Phil Zimmerman.

Naval officers tend to have a more feudal outlook that those of other services, tend to be more liberal, and less inclined to trust the general public with guns. It looks like Smith hews close to that line, and has decided he’s the man who’s going to ingratiate himself with the President by taking the 2nd Amendment down, with a good hunk out of the 1st as it goes.

You can make individuals suffer, and if you’re Glenn E. Smith you might get your jollies that way. But you can’t stop the signal.

Breaking: 3D printed pistol works, files downloadable

It’s done. And tested. The first publicly available 3D-printed firearm. The two parts not printed are the firing pin (a roofing nail) and the grip screw. (A standard AR part. You can also substitute an AR grip for the printable grip). Here are the pieces:

And here is the video of a successful test-firing with a single .380 ACP round.

Note the following:

There is risk here. ABS plastic in its various permutations is not an optimal gun barrel material. While the .380 version fired successfully in both tethered and human-fired (in the video) tests, there have been several breakages, and a 5.7×28 FN version blew itself up, with no injury reported. Build this, lanyard-test it. And we’d recommend lanyard-testing Job One to destruction, so that you can set a retire-by round count.
There is another kind of risk here, too. Cody Wilson’s prototype at Defense Distributed was made by a licensed manufacturer, and incorporated a metallic block for compliance with the Undetectable Firearms Act. As a smoothbore weapon in pistol size, this design risks classification as an Any Other Weapon (a legal term of art) under the National Firearms Act. Every NFA violation is a 10-year felony, and the BATFE prefers to pursue backyard tinkerers than organized criminal syndicates… when they’re not actually arming the criminals.
The process of 3D printing (just like any other kind of manufacturing) has a learning curve. You can expect to have teething problems, issues, and yes, print failures.
Expect the usual suspects to panic (they were already panicking over youth rifles; this should send them right over the top). But it’s pure information they’re trying to fight here. They can’t stop the signal. They’ll still try, but it’s a forlorn hope.

Here’s the DEFCAD release on “the Liberator.”

Here’s the download link (it will redirect to MEGA formerly MEGAupload — another thumb in the establishment’s eye).

Here’s the link that will let you download the whole collection of DEFCAD data. (Important note: at this writing, the current version, 4.2 “Saito,” has everything but the Liberator pistol files). It will go to MEGA and may only work with Chrome browser.

We recommend you take this freely available data and distribute it widely.

CWCID: Ars Technica.

You do realize we have just seen history made, right?

Update 1920R: here’s a story at geek.com with some more details.

Tracking Point — new videos

Late last week, in anticipation of the NRA Annual Convention, Tracking Point released new video. This one shows two features: the way the precision-guided firearm can compensate for motion of target or shooter, and the precision cold-bore first shot capability.

Right now, precision guided firearms are very expensive, and are only the province of extreme shooters and early adopters. We predict that that will change, and this kind of precision technology will be increasingly common — and much less expensive, as economies of scale kick in — going forward.

WeaponsMan

Quiet Professionals, Noisy Machinery