Posted on 03/27/2015 3:34:04 PM PDT by nickcarraway
With a 3D printer and enough thermoplastic, you can mass produce deadly plastic guns from the convenience of your own home without going through a rigorous background check.
Advanced 3D-printing technology now allows for people to make durable guns. And as far as current federal laws are concerned, it’s totally legal.
Medium writer Keith Mizokami documented his experience building not just any regular firearm, but a full-on assault rifle.
All it took was three hours and some light tools.
“I was an AR-15 grease monkey,” Mizokami wrote. “During the course of several projects, I’d built an entire rifle from scratch. But I’d never built the lower receiver of an AR-15. By U.S. government standards, I’d be manufacturing a firearm.”
The missing 20 percent he needed to make a functioning assault rifle is controlled by the Bureau of Alcohol, Tobacco and Firearms. Buying what’s known as the lower receiver requires a background check. You can build your own, free from government oversight, but it’s a tedious process that requires expert knowledge and precision. Now, a group dedicated to 3D-printing firearms announced the development of a design for a Colt CM901 rifle’s lower receiver — and it’s available for download off the Internet.
The group PrintedFirearm.com used a $500 XYZ Da Vinci printer, which is cheap compared to most 3D printers. CM901 is a step above the AR-15, capable of firing the more powerful 7.62 millimeter bullet for greater range and killing power.
A video shows the thermoplastic gun undergoing a few seconds of rapid fire, but it’s not clear if the lower receiver would hold up for any longer than that. \ Regardless, printing lower receivers is a huge step for gun enthusiasts looking to simplify the gun building process in their own home, completely undetected by the government.
Short answer, yes.
No guano? People have been doing this for a couple of years, don’tcha know.
That is the idea, of course. You can make your own spare parts, and in fact you can make your own 3D printer. Self-replicating.
That's why the federal government is working hard to choke off the ammunition supply.
Ping
LOL! ROFL! LMBO!
Seriously? 5.56 is "heavy caliber"? These twits do not know anything.
I love my poodle shooters are much as any AR-15 owners, but I would never call 5.56 "heavy caliber". That's just dumb.
You could make the lower receiver out of wood. It just holds the trigger and stock, and isn’t under a lot of pressure.
I tried to read the article. There’s a lot of both stupid and ignorant going on there. But then again it is written for San Franciscans.
Given that powdered metal manufacturing has been around for a long time, it certainly seems readily feasable.
I want one, but to use to make molds for investment casting receivers.
This week I was fortunate to be able to see a 3D printer demonstration from some of the crew from re3D.
I want one in the worst way!
the correct way is to print a wax and then investment cast
the process involves melting the wax from a plasterlike casting investment mold. That will produce a much better finish than sand casting. when tumbled with a very fine abrasive the finish will be very good
The process is called lost waxprocess. The wax can be produced by a CNC milling machine. The process is used extensively by the jewlery trade and there are people specializing carving the wax’s from the CNC . That imght yield a part with an extremely fine finish
Ummm... the article is talking about using the Colt CM901 uppers - NATO 7.62mm.
It's not 7mm mag or anything, but it'll get the job done.
“I wonder if you could print with wax and then make a sand cast for steel parts.
Yes. And you could do “lost PLA” casting.
And parts cast in brass would be easier to make than steel, and ‘strong enough’...”
No casting process is precise enough. Every cast part always needs some machining to bring it within final tolerances (same with stamped parts).
Some advances have been made via metal injection moulding (MIM) but durability results can still be quite spotty. Bolts, barrels, firing pins, hammers, sears etc have to be very hard and very tough, and precision is mandatory. Headspace must be kept with a tolerance of 0.005 inch or so, depending on the specific cartridge: too short, and nothing functions. Too long, and the gun blows up.
And at the pressures generated by the 5.56 NATO cartridge, no material is strong enough. Steel itself must be carefully alloyed, then carburized (”case hardened”), heat treated, and tempered. None of these processes are simple; even modern industrial gunmaking keeps metallurgical secrets. At the level of handmade custom gunmaking, fabricating workable parts demands the utmost skill and output is tiny.
Brass or bronze would fall far short. There’s a reason these went out as receiver materials when production of Winchester’s M1866 ended in 1897, and Colt’s Nr 3 “Thuer” ended in 1912: rimfire cartridges charged with black powder were obsolete. No modern cartridge operates at such mild pressures.
Possibilities for 3D printing of large parts like frames/receivers are intriguing, but even if all the drawbacks mentioned could be remedied, springs and magazines remain. Magazines have to be made of folded sheet metal or very precisely machined exotic plastics, both of which lie beyond any 3D printing capability.
There are no substitutes for springs. Metallurgy is at least as complex as for any other steel part.
Hardly any gun can be fabricated by these newfangled methods. It’s not a case of firing a few shots and watching the mechanism quit (which in extreme circumstances might be good enough; it’s more likely nothing will function at all. One might be just as well off arming up with an improvised “zip gun” sometimes found inside prison walls. Cruder, but less effort to make.
And while it is true at the moment that only the receiver is serial numbered, and all the other bits can be bought “legally,” regulatory agencies are quite aware of the gaps in their schemes and may move at any time to more fully control access to lesser parts. They’ve done so in the past: recall the ban on high capacity magazines that accompanied the “assault weapons” ban in the 1990s.
I own one of the 3d printers mentioned in the article. I could not find the plans to print the lower anywhere.
—or ammo—
>>I wonder if you could print with wax and then make a sand cast for steel parts.
Wax is too soft for sand casting where the sand is tamped hard, usually around a wooden mold. But the plastic can be coated with plaster and vermiculite mix, melted out and aluminum poured in. Some hand finishing would likely be required.
Not at all. Deliberate lies and deception.
bookmark
Hey, CBS, look at it this way... The printing press made it possible for you thieving statist SOBs to mass produce lies and hyperbole, a.k.a. bs, without limit or a rigorous background check. Now it's the good guys' turn to mass produce something. May the best man win.
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