Is a single-shot, open-bolt pistol or rifle legal?  I called the BATF, and the agent said he didn't have anything that said it was, but he also didn't have anything that said it wasn't.  According to him, all of the information he had about illegal open-bolt firearms was for semi-autos.  He knew of several legal single-shot open-bolt pistols and long-arms that have been made.  One was a 410 single-shot shotgun made by Big Horn Arms Corp in the late 60's.  Also, all of the hits returned from a search for the phrase "open bolt" on the BATF's web site were about semi-autos.  Anyone know for sure about a single-shot open-bolt?  Something in writing would be very nice.

The reason I'm asking is that a Sten parts kit wouldn't be too hard to build into a single-shot rifle.  You could leave-off the magwell and the cut-out in the receiver for the magazine to make it easier to build.

Aside: the agent said that if I did build the kit, I could get away with a very short barrel, because officially the barrel length is measured from the end of the barrel to the bolt.  The shotgun mentioned above had only a 15" barrel, but it was still legal because of this loophole.z

I'd get that BATF info in writing before proceeding.  You're saying that on an open-bolt weapon the barrel length is measured from the bolt face in the OPEN position?

Also be careful that whatever you make isn't readily convertible into a machinegun.

The only person I know personally that has writen to the BATF about a firearm had it taken away, and he is still facing possible charges.  This was over a beat-up, rusted $60 SKS.  I wouldn't want to be on the wrong end of their accusation that my pile of parts is a small machine gun.  I don't have the money to defend myself (that's why I'm building something cheap in the first place), and I'm 73, so 10 years in Club Fed would probably be the rest of my life.



Yes, I have been told that over the phone by three different BATF agents.  Each time, I asked if they were sure, and I got a positive response.

From the National Firearms Act:

"the length of the barrel on a shotgun or rifle shall be determined by measuring the distance between the muzzle and the face of the bolt, breech, or breechlock when closed and when the shotgun or [b]rifle is cocked[/b]."

Notice that you measure between the muzzle and the bolt face while it is cocked.  On an open-bolt, you can legally have a barrel (as measured from chamber to muzzle) much shorter than 16".z

How about this:

"the length of the barrel on a shotgun or rifle shall be determined by measuring the distance between the muzzle and the face of the bolt, breech, or breechlock [b]when closed[/b] and when the shotgun or rifle is cocked."

I would not bet the tightness of my anus on what some junior-grade ATF flunky told me over the phone.

As far as open-bolt single shots are concerned, I'm sure such a firearm would be legal if it was an original design and the bolt was not cut in such a way as to adapt it to feeding rounds from a magazine. A firearm that had a surplus Sten or Grease Gun bolt, a "dummy" mag well and a selector switch, and was just a couple cuts away from full auto, that would be a different story.

How will you assure that the gun cannot fire automatically by simply whacking off a small piece of metal. I ask because if you simply leave off the mag well the ATF may say that you could simply reinsert it and have an Unregistered MG. Which is a big No No. I have also wondered about Open Bolt myself.

When people tell me that ATF Opinions/Rulings aren't worth the paper they are written on, I think of DIASes and Open-Bolt MAC-10s which were both ATF Rulings with minimal if any legal backing.

From what I have read, yes a Barrel is measured to the bolt face.

I also remember a single shot .22LR rifle made, I think, by Colt in the 1960’s which fired from the open bolt position.  However, I believe the ATF ruling essentially prohibiting open bolts was made much later than that.  You might want to try to get a copy of that ruling.