First test of the frame. Fired prob 10 rounds through it. No issues found with it as of yet. …I was on a schedule and had to leave pretty quick so I ran my tests real quick to see how it looked then took off.
The frame does depend on metal rail inserts, and the designer has promised to release the .stl files… after a frame rail redesign.
Responding to skepticism about the part strength, he wrote:
In a post we wrote a couple of years ago but that never appeared on this blog (because it was never finished), we wrote about legendary 20th Century riflesmith and cartridge wildcatter Parker Otto Ackley, known to all as P.O. Ackley.
PO Ackley made an entire career of making what he called “improved” cartridges. Each of the Ackley improved cartridges was based on some mainstream cartridge but with an increased powder capacity and a sharper shoulder, which implies less taper in the body of the cartridge itself.
We described Ackley similarly in another post that did get published, in 2012. That of course understates Ackley’s career, because apart from all his cartridge wizardry, Ackley was a gunsmith, barrel maker, and a writer with a prodigious capacity for work.
in a new book by Fred Zeglin, this career is explored and evaluated, and Zeglin actually emulates some of Ackley’s famous experiments, including these on Bolt Thrust that are excerpted at GunDigest.com.
Since the post-WWII years, if not before, there has been an ongoing argument concerning whether breech thrust (bolt thrust) is reduced by the improved case design. P.O. Ackley has certainly influenced the argument. The definition of an improved case is pretty simple. The case body is blown out to minimum body taper, which is described by Ackley as 0.0075 per inch taper. Shoulder angles between 28 and 45 degrees are normally considered to be improved, although it could be argued that any shoulder sharper than the original parent case is improved. Finally, an improved design allows the firing of a factory cartridge in order to fireform the brass for the new design.
…a method of recording breech trust was necessary in order to go beyond the somewhat subjective experiments that P.O. Ackley wrote about in Handbook for Shooters and Reloaders Vol. I. There Ackley used a Model 94 Winchester because, as he stated, “We often hear that the Winchester Model 1894 action was designed for low pressures and is an action which could be described as ‘weak.’” The purpose of his experiment with the ‘94 was to prove that the improved case design minimized bolt thrust; that the brass will support and contain some pressure; that oily chambers increase bolt thrust; and finally, the notion that actions are designed for specific pressure ranges is a fallacy.
Zeglin conducted a high-tech version of Ackley’s tests, using a test fixture he developed, “a .30 caliber barrel with a universal breech plug to allow for adjustable headspace, and to accommodate the strain gauge utilized by the Pressure Trace.” He developed loads beyond the SAAMI pressure limit for the .30-30 Improved, and discovered that even with excess headspace, the Improved case stayed in place, extruding the primer instead of shearing its head off. Conclusions:
[W]as Ackley right about his findings?
Yes, but he may have missed a point or two.
Since .30-30 brass is thick and pressures are low relative to brass strength and case capacity, with most appropriate powders pressure is not a big problem. To be fair, we did find some powders that will develop pressure far beyond SAAMI levels for the .30-30 AI case. Because the brass is so thick, it actually cannot stretch and cause head separations due to excess headspace. In that respect the .30-30 is not a good choice for Ackley to prove that improved designs handle pressure better.
However, Ackley used the .30-30 because the ‘94 Winchester action had been labeled weak. In this respect, Ackley did prove that the ‘94 can handle anything the .30-30 or .30-30 AI can dish out, without any question.
Bear in mind that the action of the Winchester ’94 was labeled weak by Winchester, who wanted to upsell customers to stronger rifles, like the ’95, which could handle the big-game and service cartridges of the early 20th Century with no problems.
There’s quite bit more to it, so Read The Whole Thing™. In other things in the book there is something that made us order it: Ackley’s own, previously unpublished, description of his own home-made cut rifling machine. (See the Table of Contents left).
Like any highly specialized book, it’s expensive, and has potential to go out of print at some time in the future. That’s just life in specialty book markets.
How expensive? The list price for hardcover or eBook is $60, although at this writing Gun Digest is sweetening the deal with $10 off the hardcover edition, and free shipping. (Pity they don’t offer a deal on both. We prefer hardcover books, but you can take a Kindle or iPad into the shop without worrying about getting cutting fluid on an irreplaceable heirloom). For what it’s worth, we just ordered the hardcover.
While this book rates the full price (to us at least), Gun Digest publishing does find itself overstocked from time to time, and if you’re into gun books and willing to let price be your guide, they have Under $30 and Under $15 pages, too. Free shipping if you can run the tab to $50 — we bet you can. (Dunno what the shipping is to those of you dwelling in foreign lands).
We can’t discuss machine guns on this site without someone — usually Kirk — reminding us that the GI M122 tripod is rudimentary junk, and the class of the tripod world was the German Lafette 42. We’d like to steer those interested in these ‘pods to the incredible Lafette 34/42 web page of “Bergflak“ (“Mountain AA”) who is posting his work in progress on these amazing feats of German engineering.
How complicated was it? These are the parts of the lower half of the MG.34 Lafette. (The lower half of the MG.42 version was fundamentally identical).
Not complicated enough for you? Here’s 100-odd more parts from the Oberlafette, or upper half.
But wait, there’s more! 70-something parts that comprise the T&E mechanism.
Here’s a brief blurb from Bergflak:
The MG Lafette was a pretty complicated piece of machinery for its time. Some would say “typical German over-engineering”. It contains several systems that all work together. The difference between the Lafette 34 and the Lafette 42 is mainly the cradle. The weapon mounts and the trigger mechanism are simpler on the MG42 cradle. In addition it has a different bolt box. Everything else seems to be identical. This page will only describe the Lafette 34. The change from the Lafette 34 to the Lafette 42 will be fully dealt with on the Wartime development page. On this page I will briefly explain the function of each of the components that make up the Lafette. For an even better and deeper understanding of the components you must visit my page Extreme details or the pages about Evolution of the Lafette (when they are finished).
These pages explain which each part does, and pages on the evolution of the MG-34 and MG-42 Lafettes actually are complete now. Unfortunately, the page explaining the usage and employment of these tripods is not yet complete.
The whole site is worth reading already, and it stands to reason that as more information is acquired and analyzed, the site will just keep getting better and more useful.
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).
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).
Well, this is embarrassing. Never hit “schedule” or “publish” on this one. -Nose
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…
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?
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:
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.
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.
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.
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.
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!
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™:
FK BRNO says that they are an Ammunition Company that also makes a handgun.
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.
The 7.5 round delivers high levels [of] precision.
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!