Which Size?

[planeflyer21]

So when that Spartan lower receiver gets here, what size buffer tube will it take?

I see at Brownell's there are commercial and Mil-Spec sizes.  Will it make a difference as to what telescoping stock we get also?

Jon

[edgecrusher]

I believe the tubes threads that go into the receiver are the same size, the only difference it makes is for the stock style you choose. I always go milspec because the tube I like is the pws enhanced, for its qd sockets built in, drain hole, and it is just a nice solid piece compared to the others I've gone over. Plus it's billet. Here's a pic of it on my mk12 build

http://www.brownells.com/rifle-parts/stock-forend-parts/buffer-tube-parts/buffer-tubes/ar-15-m16-enhanced-buffer-tube-prod41065.aspx

[unforgiven]

Tom had a cross section of mil-spec vs. commercial mil-spec has beefer threads.I'm leaning towards pistol build then maybe goin to SBR. <dontknow>

[98Z5V]

Jon, the lower receiver doesn't care which one you use.  Commercial sized tubes have a larger outer diameter (1.17"), with the threads cut down into them.  Larger is not necessarily stronger, though.  Mil sized tubes have a smaller outer diameter (1.14"), with rolled threads. 

[planeflyer21]

Excellent!  Thanks guys!

I'm guessing that 0.030" explains why some of the M4 stocks seem a bit loose on certain rifles.

Jon