Category Archives: Weapons Technology

Bleg: World War II Suppressors

Business end of typical Maxim silencer.

Business end of typical Maxim silencer.

We’re working on a technical post on the suppressors of World War II. We know of the following:

Germany: Pistole 27(t) late war suppressor, MP 40 suppressor (limited production) K.98k suppressor (ditto).

Great Britain: Welrod, High Standard .22, Luger, Maxim suppressors (SOE was disappointed), Mk IIS Sten. De Lisle carbine.

United States: M1911A1 .45, integral M3/M3A1 SMG, Colt .380, High-standard .22 (entirely different from the British development).


USSR: none (this does not seem right, given the Soviets’ extensive use of “diversionary” and special operations elements, and their broad conception of intelligence and reconnaissance operations).

Italy: none

Japan: none

Minor powers: none

Help a brother out here. What else is unknown out there? I expect the bulk of the article is going to be on the P.27(t), which is known from several surviving samples, and the British stuff, which is very well documented.

80% SIG P229 Frames and Jigs

Don’t know anything about these but we came across this video by Robert Germanelo, and it was interesting. It made us go look up the manufacturer’s website. Eight minutes.

It takes 16 or so passes to remove the right amount of material. Note his warning about breaking the carbide cutter inserts if you try to remove too much material in one pass. We don’t know if that’s the cause, but the guy whose homebuilt SIG 229 project videos feature after the jump did indeed break one of his inserts.

The manufacturer’s website is here. It has a comprehensive rig for doing 1911 and SIG frames without a milling machine (as seen in the video above). They sell the jigs, the cast 80% frames, and completion kits made from decommissioned 9mm German SIGs. (Parts interchange seems fine between German and USA made SIGs, FWIW).

Downside? It’s a lot more expensive to do a SIG this way than to do a Glock with the Polymer80 Spectre, much like SIGS cost about 2.x Glock in the real world. Indeed, this is not a way to save money on a pistol — you can buy a 229 or a G17 for less than you can build one for, whether you went SIG with Matrix or Glock with P80. But you can’t buy one you built yourself, which to us is the whole appeal of this thing.

However we won’t be doing this until we (1) catch up on other builds and (2) recover from some gun-related spending, eh.

If you want more information on how the Matrix jig works on the P229 frame, there is a whole series of videos after the jump.

Continue reading

The 5.7 OG

Mel Johnson holding a sporting Spitfire with his rifles and MGs displayed.

Mel Johnson holding a sporting Spitfire with his rifles and MGs displayed.

Long before FN differentiated their small .22 caliber centerfire pistol round by calling it the 5.7, another 5.7 launched in a big media splash and went nowhere — even though it’s father was one of the most distinguished firearms designers of the 20th Century.

The 5.7 Original Gangsta round is often called the 5.7 Spitfire, although its official name was actually the 5.7 MMJ, after the initials of its inventor: Melvin M. Johnson of Johnson Rifle and LMG fame. Johnson began working on a 5.7 x 33 necked version of the US .30 Carbine cartridge in 1961, and introduced the cartridge in his own M1 Carbine version, the 5.7 Spitfire, in 1963. While he always intended the round to be a light, handy, high-velocity carbine round, he did round development in a bolt-action with a custom Sako barrel, achieving MOA accuracy. In the Spitfire carbine, 3″ groups at 100 yards was more standard, but Johnson did make a 2.25″ 5 shot group in 5 seconds from the carbine once, in 1962.

He had initially hoped for 3,000 fps but…

… this raises the pressures over the 40,000 PSI mark (.30 carbine standard) which, as Johnson says, “Is not so good for the M1 carbine extractor.”1

57 vs 30 carbine ammoyFinal performance was about 2,800 fps with a 40-grain full metal jacket bullet.

The Spitfire wasn’t just a rebarreled carbine. Rakusan noted that…

The carbine itself undergoes considerable change to accept this new cartridge. The barrel is relined and rechambered. The gas port is altered, giving twice the operating gas compression ratio of the original .30 carbine and about 20% more power in the driving spring, this plus cartridge design assuring positive feeding. With the 18″ barrel (Johnson also has a military version with a 12″ barrel) the overall length of the new carving is 35″, 27 1/2″ with the stock folded, 1 1/2″ longer than the requirements of the Federal Firearms Act. This short, handy length is achieved by a folding wire stock which also acts as an optional fore-end grip.

In 1964, Johnson would sell you a Spitfire from his New Haven business address for $130, or convert your M1 Carbine for $73. In addition, a shorty military/NFA version was available which, with the folding stock, was a mere 21″ long folded thanks to a 12″ barrel. In addition to the military Spitfires, some were finely finished sporting arms (NRA image below):


While most modern articles about the 5.7 MMJ and 5.7 Spitfire seem to talk it up as a military gun, the 1964 Shotgun News article stresses sporting applications: “short-range varmint hunting.”

Mel Johnson writes that he was impressed by George Lindsay’s remarks in “The Hornet’s Big Enough,” published in the 17th edition of the Gun Digest, which stated, “Even out West, fences are going up. People are closing in– and somebody is sitting on my rock.”

For too many varmint hunters the days of wide open ranges are gone, and most of the hunting must be done in semi- populated areas. Here is where the 5.7 spitfire will shine– remember, it was designed primarily as a short-to-medium-range varminter.3

Johnson was still promoting the Spitfire and seeking investors when he passed away of an unexpected heart attack on a business trip to Boston. He was 55 years old, and without him, the light went out of the project, although family tried to continue it. Periodically someone tries to resurrect the project, notably IAI in the early 90s.

The 5.7 Spitfire was tested informally by SF in Vietnam (where some carried carbines because that’s what most of their CIDG carried). No one really knows how many Spirfires were made and converted; they’re rare today, but seem to draw little collector interest, perhaps because of the wildcat round. Making the ammo is not as onerous as people think, and custom-loaded (and 5.7 Johnson headstamped) ammo is available, at a price. A Spitfire would be a nice addition to a Johnson collection.


Canfield, Bruce N. (with Robert  L. Lamoureaux and Edward R. Johnson). Johnson Rifles and Machine Guns: The Story of Melvin Maynard Johnson, Jr., and His Guns. Lincoln, RI: Adrew Mowbray Publishers, 2002.

Rakusan, J. 5.7 Spitfire, in Amber, John T. (Ed.). Gun Digest, 1964. Chicago: Follett Publishing Company, 1964. p. 166.


  1. Rakusan, J. 5.7 Spitfire, in Amber, John T. (Ed.). Gun Digest, 1964. Chicago: Follett Publishing Company, 1964. p. 166.
  2. Ibid. 
  3. Ibid. 

One Cool Tool

US Tool Manual Bolt Extraction Device 556-308Here at the Wile E Coyote Institute for Applied Aeronautics (and Gunsmiting) we occasionally find a tool we really like. Here is one such tool that not only belongs in your shop toolbox, but in your range kit, and that goes double if you’re a unit or department armorer (or a small department’s go-to gun guy), or an SF guy that has to run ranges for the Third World, or a range officer at a range open to the public (almost the same thing).

We’ve all seen the stoppage you get when an overpressure round, or maybe a nasty chamber in an unlined barrel on a bargain-basement AR, solidly stuck. It’s like the thing brazed itself in there! It’s hard to get enough leverage on a charging handle to move the bolt carrier back and unlock that damn-near-welded bolt. If the carrier is fully forward, you can separate upper and lower and attack the carrier from underneath, but if it’s back just a few millimeters it’s hard to separate the upper and lower.

You can get a similar problem with a double-feed, commonly caused by crummy or worn-out magazines. Your gun is out of action until you can reduce the stoppage.

And then there’s the circumstance, when some schmo brings the seized rifle in to the shop after getting the case stuck and then letting it sit for three months in the salty sea breeze, hoping that time heals all wounds.

The US Tool & Design Manual Bolt Extraction Device is simplicity itself: a lever with a yoke at one end that can be inserted through the magazine well and pry the bolt carrier back. That lets you open things up and get the gun back into action, or at least, troubleshoot the problem. Here’s an image showing how it works, with the upper absent for clarity:

US Tool Manual Bolt Extraction Device 02

It’s available in three versions: compact 5.56mm and 7.62mm versions, and a double-ended dual-caliber variety. (Of course these will work with other calibers on the same platform, so order the 5.56 one for .300 BLK, for example; the critical sizes are the bolt and bolt carrier).

US Tool Manual Bolt Extraction Device three versions

The dual-ended one is perfect for the shop workbench, and we could see the other attached by a clip to the rails on one’s field rifle. It would give you a way to clear this kind of stoppage in combat.

US Tool Manual Bolt Extraction Device

Here’s what they say about their tool, for which they’ve applied for a patent:

The Manual Bolt Extraction Device (MBED) is designed to be used in the event of a malfunction where you need direct access to the bolt carrier group (BCG) and the leverage provided by the charging handle is insufficient. The MBED is effectively used to clear the most common stoppages such as a double feed where the second round is wedged above the BCG. The MBED can also be used to clear an over pressured round or any stoppage where the casing is stuck in the chamber and has seized function of the rifle.

The MBED can be used to aide in any stoppage where direct access to the bolt carrier is needed. The AR-15/AR-10 platform does not allow for the user to have access to the bolt like the AK47, M1 Garand or M14 style rifles. The charging handle gives minimal leverage to the bolt carrier group and requires multiple tools and at least two individuals to clear these stoppages. The MBED is a single tool that a single individual can use to get the rifle back into working order in a short amount of time.

This is simple and that’s what makes it brilliant. We’re ordering one for the bench and one for the range bag, at least until we can figure out the rail clip that we want to make. You can buy the MBED here:

The 3D Printing Revolution is Over, and other Developments

We’ve had a few interesting developments in home and small office firearms prototyping lately.

The 3D Printing Revolution is Over, Part I

red_flagIn a way, the 3DP revolution is over. The revolutionaries won. Every firm in the industry that we have personal knowledge of, from the great (exchange-listed Ruger) to the small (single-digit prototype shops) is using 3D printing in prototype development or even in manufacturing. For example, Ruger’s investment-casting shop, which also casts for competitors and other third parties, Pine Tree Castings, is directly printing lost-wax patterns on two industrial printers; time, energy, and recycling effort are all signally reduced.

The firms that are not using this technology are very small, practically one-man shops, and even they are often using 3D computer design tools and CNC. For the same reason that even the starving writer in his garret is hammering on computer keys and not his granddad’s Underwood: new tools have produced an explosion in individual productivity.

Productivity and Computer Technology

Computers directly enable productivity. For example, imagine this blog in the pre-computer (or even, pre-Internet) era. The “posts” or items would be typed on paper, then reproduced into a newsletter, and mailed to subscribers. It would lose immediacy and volume for sure; it would take us much more work to produce much less.

Computers also indirectly enable productivity by increasing information flow, both in terms of volume and rate. (An ironic by-product of that is that a whole new application for computers became necessary: tools to search, sort and amplify what is to any particular user his desired signal amidst all the noise (some of which is pure noise, but most of which is someone else’s desired signal). Economists have had great success in recent decades by describing economic activity in terms of flows, not of 18th-Century concepts like capital and labor, but of information. Freeing the flow of information from unnatural restrictions generally benefits the society and the individual. It usually scares the pants of some people, especially the ones who used to be able to control the flows.

Computers moved much more slowly into actual production of tangible products, but they’re there now, and making a similarly revolutionary change on the factory floor that Steve Jobs promised to “knowledge workers” in 1983-5 when he introduced the Apple Lisa and, later, the Macintosh Office. Some of those ideas misfired in their first implementation (early Lisas and Macs are collectors’ items today), but the marketplace iterated rapidly and effectively and still does.

Today’s computer manufacturing technology is still relatively primitive, when compared to its potential; we’re about where Steve’s “Macintosh Office” was 30 years ago.

Meanwhile, in Washington DC & Around the World

Just as manufacturing of products becomes disintermediated and dissociated from large integrating manufacturing/marketing/distribution organizations, we have our version of a Luddite spectacle. A bunch of politicians, most of them captive of the economic and political concepts of prior centuries, are making a childish display of themselves, and demanding restrictions on production and ownership of a product, firearms. But they are asking the impossible: guns can be produced under the most precarious of conditions by the most primitive of shops. They do this because they want to redirect anger and retribution away from the actual generator of the recent outrage, Wahhabi/Salafi Islam, and towards targets whose destruction they would find more personally gratifying.

The guy who last changed your brake pads and wiper blades probably has everything in his shop necessary to produce automatic weapons. In fact, another terrorist outrage you may not have heard about recently occurred in Israel where two assclowns inspired by Islam attacked a restaurant with submachine guns.

Back in February, more homebrew SMGs were used in attacks on Israeli cops.

Damascus Gate SMG 1

The SMGs, made under embargo conditions in clandestine workshops in the lawless Palestinian territories, were improvised weapons. (One of which did fail during the attack. Testing is an aspect of manufacturing that technology can’t replace).

You certainly heard about the murder of left-leaning British politician Jo Cox, in the land of no handguns, Great Britain. Cox was killed with a crude improvised pistol based on an ancient US Army improvised guns manual.

Non-factory guns can be very sophisticated

Don’t take our word for it, just peruse the Impro Guns blog. Here’s a Thai pepperbox in .22LR.


This next picture is not a TEC-9. Take a good look! It’s a clandestine-shop knock-off open-bolt SMG, seized by cops in Canada last year. Restrict all guns and “prohibit” the scary ones, as Canadian laws do, and this is what anyone who wants a gun might as well build. He’s as well hung for a sheep as a lamb, eh?


Here’s a shot of Browning-style pistols produced in a one-house clandestine factory in Talcher, Odisha, India that was seized by police in the summer of 2015.

Indian Impro 2015

And here’s video of a (US, legal) home-built .25 pistol.

Here’s the build of the same (18 minutes). Tools used include a drill press, welding equipment and circular and saber saws. He does use some well-chosen cutting tools, like end mills and reamers, and uses a rifling machine of his own manufacture. ses At one point he improvises an end mill from a drill bit (per the plans he is using). He uses the name “Clinton Westwood” which we’re sure is what his mother named him; his YouTube Channel, Clinton’s Cheap Workshop, is full of must-watch TV.

Clinton’s new adventure is making a larger, 1911-styled .380 blowback pistol. He just started in April and has made good progress, so go to the YouTube channel, click Videos, and enjoy.

You might want to archive the videos, in case YouTube (which is owned by Google, which is either owned by or owns the Clinton — Hillary, not Westwood — campaign) disappears them and unpersons Westwood in the future.

The 3D Printing Revolution is Over, Part II

In another way, the 3DP revolution is over. Many of the revolutionaries of the first wave have gone much more quiet, perhaps because they’re involved in other things, or perhaps for some other reason. Maybe they’re under pressure from a lawless DOJ determined to find terrorists everywhere except among Islamic terrorists!

Cody Wilson? Tied up in a lawsuit, his new book, and the GhostGunner project. Now, the project isn’t idle. Here’s a new video posted this week on the GG2:

And the company released a new manual for the GG1 and GG2, and new software, on 1 June, including the first MacOS version of DDCut.

James R. Patrick? Website gone, although his .STLs have made it into the distribution. Have Blue? Hasn’t tweeted since December. Is he a Norwegian Have Blue, pining for the fjords? ArmaDelite? Not since April 7. Ma Deuce? Showing a heartbeat, at least. He posted a YouTube video in his channel about two months ago, for the first time in a year.

But RollaTroll is still with us (even if his last tweet was a Weaponsman link a couple weeks ago).

And the thing is, it doesn’t matter if some of the original founders of the 3D printed arms movement 3+ years ago have gone silent, gone Hollywood, gone to ground, or gone underground: a new generation is supplementing, and where necessary, replacing them. And the new generation is larger, and the generation they energize will be exponentially larger still.

The genie’s out, and anybody waving a bottle and muttering get-back-in incantations at this point just looks ridiculous.

3D Printed MP5 Lower, Update 1 (Installment 2)

Here’s Guy In A Garage again, with a follow-up for the 3D printed prototype he cooked up that allowed AR-15 lower receiver parts to operate an H&K MP5 (he’s using a clone). We had his first video on the MP5/AR hybrid last Wednesday, so go there to catch up if you need to, before coming back to see Part II of this adventure in home manufacturing.

In Update 1, the lower is much more developed. It’s still missing one thing to be mature, though.

The one thing that’s missing? An ejector. The MP5 ejector is a quite ingenious thing that always provides a good stout kick

Guy in a Garage has been busy! He’s also posted 3D backup sights for 1″ scopes. The files are available at SendSpace; he got the idea from this article in Recoil, the gun magazine best remembered for its former anti-gun editor and Jack-the-Lad attitude.

And that’s not all. He also had this followup on a 10/22 receiver project…

… and a super-lightweight home-made carbon fiber handguard.

If you’re interested, you can follow all his videos here:

Wednesday Weapons Website of the Week: Engineering Design Handbooks, Guns Series

We’re pretty sure we’ve called DTIC a W4 (Wednesday Weapons Website of the Week) before. The Defense Technical Information Center is kind of like the granddad’s attic of DOD information — full of cool stuff, but not remotely what you would call organized.

But today we’re going to steer you to something specific in the military’s attic — a series of engineering design documents from the 60s and 70s that will enhance your library in .pdf format, and that cost you only the time and bandwidth to download them. (If you’re American, you’ve already paid for this with your tax dollars. If you’re one of our global readers, they’re free (as in beer and speech) to you, too; if you’re so inclined, thank a Yank.

Yeah, ‘Murica. We give away more free bleeep before 0900 (well, technically, at 2200) than you’re ever going to get out of Burkina Faso or Lichtenstein.(We’re sure they’re lovely places, though, even if not at the forefront of small arms design.

The books in question are from an expansive series of Engineering Design Handbooks that were published by the US Army Materiel Command (the successor to various Ordnance headquarters that were consolidated decades ago). While there are a great many EDH’s (the Environmental one is especially good on corrosion) the ones we are interested in fall into the Guns Series.

This search finds at least some of them:

We don’t know how many there are/were (but we bet Daniel Watters does). Four volumes that turn up are:

  1. Guns Series — General. The history of guns, their classifications, and sample gun design problems). August 1964.
  2. Guns Series — Gun Tubes. Regions of the tube, thermal and pressure stresses. There’s some interesting continuity and discontinuity between small arms and artillery tubes. Ever consider the effect of rifling torque? It’s in here. February 1964.
  3. Guns Series — Muzzle Devices. If you’ve ever wondered what they were trying to do with that silly-ass cone on the M2 carbine, or wanted to know how much recoil you can reduce with a muzzle brake (a limited amount, because the brake can’t affect anything until the projectile exits the barrel, by which time most of the recoil is history already), this is your answer. May 1968.
  4. Guns Series — Automatic Weapons. Almost 350 pages of design engineering goodness from an overview of AW types to angular velocity calculations to  what makes a good belt link. February 1970.

And when you’ve learned all of that? Then, you can start looking at the “explosives series.” Heh.

We, for one, Welcome Our New Polymer Overlords

Let’s have another one from Guy in a Garage. In this case, he’s test-firing a James R Patrick Songbird .22.

You see some of the limitations of the 3D printed plastic firearm here.

But you also see some potential.

Barrels were never going to be the best test case for fused filament fabrication type 3D printing, for the same reason that even commercial manufacturers deeply committed to polymer firearms parts have never produced polymer barrels.

Polymer receivers go back almost 60 years to the Remington Nylon 66 (1959) and its derivatives, which had unitary receivers and stocks of DuPont Nylon 6/6, a polyamide that was then one of the toughest injection-moldable plastics available. Polymer handguns go back nearly almost 40 years — to 1979-82 and the development and launch of the Glock 17. Millions and millions of polymer frames have been made, but zero commercial polymer barrels.

There have been experimental barrels that were made of wound fiberglass, or fiberglass around a metallic rifled liner, such as the ones that Armalite of Hollywood, California experimented with for shotguns and some early AR-10 prototypes.

AR-10 barrel blowout Image 12590-SA Springfield

These early experiments left some of the Springfield greybeards wondering if Armalite was sourcing parts from Acme…


177913-1…and having them installed by graduates of the Wile E. Coyote School of Gunsmithing.

Modern composite technology such as carbon fiber filament and tow, and filament winding machinery, has finally brought the technology into line with Armalite’s vision. Carbon fiber (lined, of course) barrels have also been adapted to modern rimfire arms as well.

What does this mean for the future of polymers? Well, it’s a fact that after all these years, good old Nylon 6/6 is still a competitive material for high impact uses. What has happened in the injection molding industry over that span of time is increasing use of inserts and overmolding to make molded parts out of multiple materials.

This is almost certainly the wave of the future — or one wave of the future — in 3D printed firearms parts. Many printers now have the capability to print in multiple materials or to pause for the insertion of an insert (such as a threaded socket for a screw; you’ve probably seen molded plastic parts with inserts like these).

We can still expect 3D printing to be used for convenience, short runs & micromanufacturing, customization and personalization, prototyping, making jigs and fixtures, and making molds and patterns for traditional manufacturing processes.

But if you really want to, you can make a gun out of it.

Another Way to Use 3D Printing

Chuck of GunLab and his friend Orin have a dream: to wit, bringing a rare and “dead” single-shot design, the Remington Hepburn, back to life. To do this, Chuck got a scrapyard special Remington Hepburn and reverse-engineered the rusty, pitted action into SolidWorks. Then he passed the solid model to Orin, who tested it by 3D printing a model.

First print success!

Now, we’re not sure what plastic he used here. If he were to do it in PLA, he could have it lost-PLA cast. It would take a professional foundry to do it in steel or iron, but it might be strong enough (and very beautiful) if done in silicon bronze. (Of course, many modern foundries doing investment casting can now work direct from an STL file, printing in wax using a specialty printer).

They followed up with a Phase II: Orin designing a cutaway receiver and the various internal parts:

GunLab pre printed partsAnd then printed them:

GunLab Orin printed partsThis way he can check (and observe) the fit and the quality of his reverse engineering.

These are all good (and soon to be standard) uses of 3D printing technology as a resource extender, time saver, and general force multiplier for design, engineering and manufacturing.

Chuck, for one, is sold. He just took delivery of his first 3D printer… he got a great deal on a discontinued model… and has been machining the aluminum alloy parts it needs to replace its brittle, failing plastic ones.

3D Printed MP5 Lower/Trigger Group Prototyping

We’ve shown you before some of the cool stuff Guy in a Garage gets up to and posts on his Yoot Oob channel. This time, the yoot’ is doing something very interesting — prototyping a lower for an MP5 that will take conventional AR parts.

Is that even possible? you may ask. Be answered:

It’s an early development mule, but it shows every sign of working. An MP5 that can take AR trigger components is potentially a very useful thing.

The 3D printed mule is expected to lead to a 3D printed prototype, which would then lead to a production part in metal. There are many ways to make that metal part — one could bend sheet metal and add small parts to make a weldment, machine the part from billet, or even 3D print it in ABS and then lost-ABS cast the part.