Rear trunnion on pistol AK

[Ryanxia]

I'd like to take an AK pistol (like a PAP) and put an AR15 pistol buffer tube on it along with the Sig stabilizing brace (I know they make AK specific braces but I don't want one).

My concern is, to do this I would need to add a standard rear trunnion to the back of the AK, which, being able to take a rifle stock at that point, would be illegal (I have other AK's so I'm sure I have spare stocks lying around). I would add the AR15 buffer tube adapter to the rear trunnion like you would with an AK47 rifle.

Am I correct? Any better ways to put an AR pistol buffer tube on a pistol AK? Maybe if permanently joined the rear trunnion with the AR15 buffer tube adapter that would be legal?

 

[Sam1911]

I believe the problem would then be that you've added "back" into the design the attachment point for the common buttstock. It really doesn't matter that the thing you plan to install there isn't technically a buttstock.

But this is all brave new world stuff, with the BATFE approving various elements that skirt closer than we would have believed possible to Title II of the NFA. I'd be very surprised if you asked and they said the rifle trunion is now ok. But I was pretty surprised that they approved the SIG "arm brace", the 3MR trigger, the slidefire stock...so who knows?

 

[Strahley]

I could see it going either way. I would write the ATF and get something in writing

 

[Ryanxia]

I agree Sam that adding it back in by itself won't fly. What about the idea of permanently joining the rear trunnion to the AR buffer tube adapter? At that point it wouldn't be able to take a regular AK stock right?

Me thinks there needs to be a one solid piece that takes an AR buffer tube but goes on the back of an AK47.

 

[Ryanxia]

So after doing some thinking I think I figured it out.

Herra makes the side folding buffer tube adapter, if the rear plate on the pistol AK is cut and threaded to take the other end, the adapter can be screwed into the back of the AK, tac welded to stay in place, and a pistol buffer tube and Sig brace installed onto the adapter.

I don't see any legality issues with this, anything think otherwise?

 

[AmEngRifles]

CAI makes an Arm Brace adaptation (waiting for the Sig lawsuit) that requires no drilling or modifying of the rear trunnion. It goes under the pistol grip in the same fashion as the single point sling adaptors. That seems like the right way to go. If CAI stops selling them or the whole thing is shut down due to lawsuit, then it is easy enough to return you AK pistol back into a true AK pistol, not one that has holes in the trunnion or tack welds to boot.

Tack welds! Now that is a NEW conversation all together! lol. How many ways can we modify with a Tack Weld!!?? Almost endless fantasies come to mind.



The problem when you cobble together something yourself is that the liability now falls on you. If you purchase a complete PAP pistol with ARM Brace or go with the CAI Arm Brace on a Draco or PAP, there is a bit of a legal firewall. CAI should have already received approval to produce these and put on PAPs. If legal precedent ever changes, you can quickly get back in line with legal, if that is where you are more comfortable.

 

[rdhood]

It seems like any trunnion that would allow you to take an <accessory-of-your-choice-that-attaches-to-rear-of-trunnion> would also allow you to mount a rifle stock because someone could make a rifle stock to fit the mount.

Is having a hollowed out cavity and tang on the back of a pistol patently illegal?

 

[Arizona_Mike]

I think you are over thinking a bit. In 2011 the ATF clarified their position on constructive possession in letter 2011-4, to the "close proximity" and "no other purpose" standard.

Mike

PS. Just like Sam, they have been surprising me at every turn the last several years. Porcine aviation is not far behind.

 

[Ryanxia]

This is an old thread.

I went with the CAI brace because it was cheaper than the Herra adapter (even though the folding aspect would be cool).