Category Archives: Weapons Technology

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 — 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 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.

What’s after HMMWV?

Here’s a program that doesn’t seem to be a boondoggle: the Joint Light Tactical Vehicle outperforms its predecessor in the performance measures proven vital in combat: protection and mobility. And the troops seem to like it, if these interviews which appear to have taken place at the annual Association of the US Army (AUSA) show are anything to judge by.

Thanks to Our Traveling Reporter, who is traveling (as usual) and wrangling with the Dreaded French Language (which is something new), for the link.

The biggest beef we have with any of these spam cans is that you lose situational awareness while you’re in there. The Army is working on technology to get you a visual picture of your surroundings, an enhanced visual picture (drawing from everybody’s sensors so you can see through obstacles and observe things not in your line of sight), but you lose the three-dimensional and time-domain grasp of sound, smell and sensation. There’s a reason that tank commanders always risk their necks up and out of their hatches until the lead pollution, DU defilement, and VT-fuzed HE precipitation is about to get thick.

Of course, the GIs are perfectly happy. They would like it to fly. 

Maybe by century’s end?

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

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.

Thump with TRUMP (No, this is NOT political)

Not the least bit political… this is an entirely different TRUMP. The guy getting sworn in Friday is Trump. TRUMP, all caps, means Training Re-Usable Mortar Projectile, and here you see a demonstration of unboxing a live M2 60mm Mortar, setting it up, and setting up TRUMP rounds and firing them.

The propellant and the on-target pyro charge are 20 gauge shotgun shells loaded with black powder. Strict limits on powder weights must be observed, lest your TRUMP rounds cross the threshold where they’d become unregistered Destructive Devices, a felony violation of the National Firearms Act. This limits the range of the mortar and the spectacle of the rounds’ detonation, but it can’t be helped. The mortar itself is a registered Destructive Device, and in the USA that is handled under the NFA like a machine gun or silencer would be, requiring ATF registration prior to possession, and a $200 transfer or manufacturing tax.

“Yeah, but,” we can hear you thinking out loud, “Where are you going to get a mortar?”

They’re around, but if your local gun store is fresh out, try the guys who made the video, Ordnance.Com. They have a website and a YouTube channel, but they also have M2 mortars just like this one and TRUMP rounds for sale on Gun Broker.

They also have 81mm TRUMP rounds, and older-style 60mm inert, reusable rounds. You can use the 60mm rounds in any 60mm mortar, and the 81mm rounds in any 81 or 82mm mortar.

TRUMP. Make Artillery Great Again.

Wednesday Weapons Website of the Week: Liberated Manuals

We’re going to be the soul of brevity on this one, because there’s no magic here at Liberated Manuals, it’s just one more source of public-domain military manuals.

They describe their raison d’être as follows:

This website is a comprehensive source of government manuals, in PDF format, free to copy, republish and distribute as you want. The goal of this website is to “liberate” government manuals from the dirty hands of CDROM selling mafia. All manuals are offered at no charge.

Sure, it’s an ugly and basic website, but on the gripping hand, it’s free stuff. What’s not to like?

There’s a list and a search function at the home page. Some of the manuals include (these are all .pdfs):

And one of our personal maintenance favorites:

There’s a lot more than just gun manuals, though. Go there and take a look around!