View Full Version : Long buffer tube on AR pistol?

07-12-2010, 9:15 AM
Most people run short, "purpose built" pistol length butter tubes on their AR pistols but I prefer the longer A2 rifle tube. I understand that the threaded hole at the rear of the tube could be construed as "accepting" of a detachable stock. So the question is: Can I legally use a modified (no threads at the rear) rifle buffer tube on my pistol build? Some of you might be asking "why" well there are a few reasons including balance, ease of shooting, way better follow-up up shots (its my pistol and I can shoot it anyway I want! :D) and slightly smoother running. If you are just shooting from the hip answering me and don't really know, don't. And yes, I know legal advice should be taken with not but a grain but a whole spoonful of salt. THX

07-12-2010, 9:41 AM
I wouldn't.

We do know VATF doesn't regard AR pistol receiver extensions ("buffer tubes") as buttstocks - otherwise everyone with
a standard AR pistol would be regarded as having an SBR.

I don't think we know how thiis plays out for using a longer tube in either Fed law/case law, nor CA law. [CA gun law has
its own SBR law which broadly tracks Fed law but could end up going sideways - look how CA's Rooney decision ended
up differing CA law on 26" overall length from the Fed standard for folding-stock rifles (in CA: measure rifle OAL w/stock
closed; BATF/Fed std: measure rifle OAL with stock open, the latter of which allows rifles to be shorter length in folded
configuration when in free states)]. Also it just "smells worse" using a rifle tube on a pistol and then still saying it's not
a rifle - a bit of mental contortion. I think we need to stay on the other side of the line.

To me, and until found otherwise, I think you want something that doesn't look at all designed for any "shoulderability":
with a short tube, you're really having to contort yourself to even try to get to a rifle-like hold, and the BATF considers
it legit for pistols. That gives you good protection. I also think folks - just for for (legal) safety's sake in these regards
- shouldn't put "comfort thingies" on their pistol buffer tubes as that could perhaps go sideways under CA law.

So keep your pistol receiver extension; work on your gun's performance thru its gas system & buffer plus bolt carrier weight.

07-12-2010, 10:09 AM
While Bill makes a very interesting point about CA laws, that view is a little too conservative for me. An extention tube is an extention tube, it cannot be a buttstock. That only leaves SBRs or constructive intent for SBRs, that is an easy thing to fix. I would make that tapped hole in the back for the buttstock dissapear, probably the best thing you could do is put a sling swivel in there. It would also probably be best to put some foam over the tube as well. That would take some serious work to fit a buttstock over that.

I tried it by putting a rifle length tube and no buttstock on my 16'' AR and I found the longer tube awkward. Try on your rifle first, it doesn't feel right, the tube is just too long to be used alone but then again I require a very short LOP.

There is a letter somewhere on AR15.com from the ATF confirming that the extention tube is not a buttstock but an important parts of the operating system. I'll see if I can find it.

07-12-2010, 10:14 AM
Found it on here thanks to 69Mach1:


07-12-2010, 10:20 AM

I'm glad you posted that letter.

That does clean up the issue of the Fed matter, but it could leave it open for similar CA matters. I know I sure as hell could shoulder a carbine or rifle-length buffer-tube'd AR and it'd be a useable shoulderable firearm.

The constructive possession comment in the letter was notable, and AR pistol owners need to be aware of it in relation to stock possession (just as rifle owners need to be aware of it in relation to pistol uppers).

07-12-2010, 1:54 PM
The above letter from the Fed DOJ makes clear that running a "carbine" buffer is a non-issue so long as a stock is not readily attachable. It seems I am in the clear so far as the Feds are concerned.

As BWeise points out things could go sideways here in the great state of CA (like when can't they!). We simply do not know where an aggressive prosecution would go with this if one of us goes "for a ride". It seems to me the difficulty, like most of these issues, has a lot to do with risk aversion and size of your legal war chest.

I take to heart, as others should, that having a shoulder stock with you without a rifle in possession is a significant risk.

New information is encouraged, particularly with regard to CA laws. Thanks for the input!