AR buffer tube maximum size?

[OrenG]

Hello,

I'm currently working on a project that involves an ar15 lower receiver based design. Already discussed this in the legal section and as far as I can tell, it's legal. Anyways, I'm creating an air rifle using a ar15 lower receiver type design, only for the mag well, stock attachment and pistol grip attachment as well as the availability of parts. What I plan on doing is housing an 88 gram co2 cartridge inside the buffer tube. However I have found that the 88 gram co2 cartridge is 1.38" in diameter and the largest buffer tube I found was 1.17"...So my question is, if I make a 1.39" diameter buffer tube, will stocks still fit on it?

-Thanks,
OrenG

[telcolineman]

None will fit, Milspec are smaller than commercial. I am pretty sure the 1.17" is the commercial size, You will have to fab somethnig

[J_Rock]

[-hanko]

None will fit, Milspec are smaller than commercial. I am pretty sure the 1.17" is the commercial size, You will have to fab somethnig

Correct, but that's the o.d. Back to the drawing board.

-hanko

[NeoWeird]

Hate to burst the bubble even further, but the buffer tube threads on an AR receiver are 1 3/16" x 16 tpi. So you're talking specialty threads/receiver tower to fit something over 1 3/8" in diameter. The AR receiver is just over 1 1/2" in that area, so you have SOME play, but not much as you'll end up with about 1/16" wall thickness in that area - not much. An A2 stock is also not even 1 3/8" in width so you couldn't even bore it out to hide the canister in it.

You're best bet is probably going to be to use some sort of reducer (you might even be able to install some regulator valves to avoid drops in pressure (assuming you're working on a semi or full auto air gun). Once it's out of the actual receiver tower, you could have a thin walled steel tubing (for strength at minimal width) act as a faux buffer tube, only the rear of the faux buffer tube would be open so you could screw in the larger 88 gram air canisters (may need to create some type of socket/spanner wrench to get it properly. Then it's just design your own stock around the larger buffer tube, similar to the ACE skeleton stock, or chop and modify an existing stock to fit the new size tube.

[OrenG]

Hate to burst the bubble even further, but the buffer tube threads on an AR receiver are 1 3/16" x 16 tpi. So you're talking specialty threads/receiver tower to fit something over 1 3/8" in diameter. The AR receiver is just over 1 1/2" in that area, so you have SOME play, but not much as you'll end up with about 1/16" wall thickness in that area - not much. An A2 stock is also not even 1 3/8" in width so you couldn't even bore it out to hide the canister in it.

You're best bet is probably going to be to use some sort of reducer (you might even be able to install some regulator valves to avoid drops in pressure (assuming you're working on a semi or full auto air gun). Once it's out of the actual receiver tower, you could have a thin walled steel tubing (for strength at minimal width) act as a faux buffer tube, only the rear of the faux buffer tube would be open so you could screw in the larger 88 gram air canisters (may need to create some type of socket/spanner wrench to get it properly. Then it's just design your own stock around the larger buffer tube, similar to the ACE skeleton stock, or chop and modify an existing stock to fit the new size tube.

Hmm well in that case I'll just find another solution. Would have been nice to hide it in there and use existing stocks but oh well.