First 3-D-printed gun fired, but its digital blueprints make bigger bang

[Ed Anger]

I have enough trouble with those 3D puzzles.

[Ed Anger]

Files removed at the request of the DoD.

[Brazen]

The Department of State's Office of Defence Trade Controls Compliance, but close enough

[derspiess]

That's from a 3" barrel. Smooth or rifled is really irrelevant at PB range. Besides, all things being equal, a smoothbore would be faster in terms of velocity. Less accurate, however.

The barrels don't look even 3" to me (assuming the chamber is integrated into the barrel).  And you're assuming there is a tight fit between the bullet and smoothbore barrel-- I would wager that there is some space there to prevent excessive pressure.  Finally, with the the barrel being plastic there's bound to be some "give" or slight expansion that you wouldn't have with a hardened steel barrel.  That's going to let some gases leak out.

Fucker should have been considerate enough to at least put it through a chrony so we'd see the velocity to confirm




FWIW, this dude kinda backs up what I said about the gun being dangerous to the user.  Yeah, in the demonstration it didn't explode and he says in the other shots it didn't, but it's not something I would want to take a chance on: http://www.guardian.co.uk/technology/2013/may/09/3d-printed-guns-user

[11B4V]

FWIW, this dude kinda backs up what I said about the gun being dangerous to the user.

This be a true statement.

[DontSayBanana]

The barrels don't look even 3" to me (assuming the chamber is integrated into the barrel).  And you're assuming there is a tight fit between the bullet and smoothbore barrel-- I would wager that there is some space there to prevent excessive pressure.  Finally, with the the barrel being plastic there's bound to be some "give" or slight expansion that you wouldn't have with a hardened steel barrel.  That's going to let some gases leak out.

Fucker should have been considerate enough to at least put it through a chrony so we'd see the velocity to confirm




FWIW, this dude kinda backs up what I said about the gun being dangerous to the user.  Yeah, in the demonstration it didn't explode and he says in the other shots it didn't, but it's not something I would want to take a chance on: http://www.guardian.co.uk/technology/2013/may/09/3d-printed-guns-user

Me either, given that ABS' tensile strength is only in the ballpark of 4,300 psi.

[CountDeMoney]

FWIW, this dude kinda backs up what I said about the gun being dangerous to the user.

This be a true statement.

No shit.  Look at Caliga.

[DontSayBanana]

Basically, knowing the tensile strength of ABS, what likely happened was that the chamber and barrel were cracked by the first shot and exacerbated by the subsequent shots until failure.  Still, knowing that cartridges can be loaded for rimfire pressures up to 40,000 psi, I wouldn't want to take the chance that the gun won't blow up- especially given the 3d printing process is granular in nature, so even designing this as a throwaway weapon is problematic, since you can't necessarily plot where the stress points in the chamber and barrel are and how they'll deform.