There’s been a lot of angst amongst the gun prohibitionists this week, and the latest comes from the revelation that the first firearm made entirely with a 3D printer was successfully test fired just a few days ago.
The reaction from the gun-grabbers was hardly surprising: they’re moving to make 3D printed guns illegal. Of course we all understand how meaningless such a law would be, but they have to do something, by golly!
You may not be aware of this, but making guns easily in a garage has been the goal of many gun designers over the years. Ian at Forgotten Weapons recently featured one such rare and obscure arm: the Croatian Šokac submachine gun from the 1990s.
It is not an anomaly; building a gun using primitive machine tools is often the norm in places where armed resistance is a necessity, arms are scarce, and there is no factory to supply the need.
The Šokac can be made in a garage using not much more than a medium-sized lathe and milling machine; any reasonably skilled gunsmith could construct one with the normal tools of the trade, as could many automobile mechanics or one of the tens of thousands of metalworking hobbyists who have a machine shop in their home. A high school metal shop could turn them out en masse.
The only real difference between the Šokac and the Defense Distributed “Liberator” pistol is the skill level needed to build one. When you compare the cost of the minimal hardware necessary to make a steel gun and a plastic one, the numbers are very similar - it’s the skills necessary to do so which differentiate the two. The Liberator can be made by anyone with a decent computer and the funds to acquire a 3d printer. (Wait until the machinists and the 3D printer owners get together…)
In other words, this story isn’t really news. People have been surreptitiously building firearms since the dawn of the gun, and that hasn’t changed. It’s just gotten to the point where one doesn’t get grime under their fingernails doing so.
It also underscores the futility of trying to outlaw firearms altogether, which is the overt goal of many anti-Second Amendment zealots. People will find a way to make them, right under the noses of the people who say they can’t.
-=[ Grant ]=-
I suppose you have to be of a certain age to understand the humor in today's title. Still, that's what today's Surprise is about - sockets. As in sockets that go onto socket wrenches.
Most men have a collection of sockets; I certainly do, as it seems I'm always working on something around our place: cars, trucks, tractors, lawn mowers, you name it. The primary tool for all of them is the socket set. I use mine constantly, but have never given a thought to how the things are made.
Thanks to the miracle of television, I've found out. The show "How It's Made" visited the Snap-On tool factory and filmed the production of sockets. I wish they'd have done some slo-mo on the broaching machine, but at least it shows how the process works.
(Since we’re on the subject, I’m going to put in a plug for my favorite all-American maker of sockets and ratchets, Wright Tools, and my favorite place to buy them - Harry Epstein, Inc.)
-=[ Grant ]=-
Wednesday, September 05, 2012 Filed in: General gun stuff
There are a number of ways to cut spiral grooves in metal tubes, but the oldest is the cut rifling machine. A cutter is pulled through a barrel, simultaneously cutting and rotating as it travels. How is the tool guided and controlled? Why, by the rifling machine!
The Truth About Guns posted this very cool animation of a sine-bar rifling machine at work:
Notice how the cutter is rotated by the sine bar as it travels (which controls the twist rate); the barrel is rotated between passes (which controls the number of grooves - in this case, it appears to be a five-groove barrel); and the bump stop moves forward to push the wedge further in, which increases the depth of the cut (the cutter can't dig out the full depth of the groove in one pass; it must take off only a very small amount of metal, measured in ten-thousandths of an inch, at a time and needs to be adjusted on each pass to do just that.)
Now, imagine instead of the straight sine bar you had a curved one; you could make the cutter rotate more at the end of the cut than at the beginning, which is how gain twist rifling is made. Cool, huh?
The animation is based on a mid-19th century Robbins and Lawrence machine. Slightly more modern machines, like those from Pratt & Whitney or Diamond look somewhat different - though if you watch closely you’ll be able to pick out all the functions shown in the animation. Here’s a real Diamond sine bar rifling machine in action:
Today these machines are hard to find and very expensive. The Diamond shown in the video may look fairly new, but we know it was made sometime between 1890 (when they adopted the form of their name shown on the machine) and 1926 (when the company went out of business.) It’s possible, however, for a suitably skilled machinist to build one in his garage, and many have. There are even people selling plans and DVDs that will show you how to do it!
-=[ Grant ]=-
Perhaps it's my background in watchmaking, but I've found myself gravitating to Swiss products over the years. The vast majority of my precision measuring tools are Swiss, as are many of my screwdrivers and assorted precision hand tools. Their products are not frilly, but purposeful and built to an incredibly high standard. Though my Austrian Emco-Maier lathe is a perfectly serviceable machine, I still lust for a Swiss Schaublin 120-VM (or, dare I say, an SV-130 Mk. III ?)
Given my fetish for fine machinery, you can imagine my delight that Forgotten Weapons is doing "Swiss Week" - a multi-part look at Switzerland's lesser-known entries into shooting history.
Take, for example, the LMG25. This magazine-fed medium machine gun is chambered in 7.5x55 Swiss, the same cartridge used by the (relatively) common Swiss Karabiner Model 1931 (K31). Like the K31, the machining of the LMG25 is exquisite - which is readily apparent from the photos. I can't stop staring at it.
Ian even did a tear-down video. Even the magazine port cover is precisely made and nicely blued. Listen to the action sound as he cycles the bolt - smoooooooth.
Now I want a Schaublin even more. Damn you, Ian!
-=[ Grant ]=-