Ar-15 Buffer Tube Spec Question

[altheman2]

Ok i am a little confused on this. I have a DPMS lower, I was looking at stock options. There is a Mil-Spec and a Commercial Spec. I have heard it many ways now after a search on the internet. Does it matter which one i get for my lower as long as the stock goes with it?

[WarHorse1961]

There definitely is a difference in the buffer tube size, but as long as you get the tube with your buttstock, you should be good to go.

[00BUCK]

The lower will take either - the thread size is the same. The tube size is the main difference - just make sure your stock matches your tube. FWIW I like mil-spec better, the threads just seem to fit much better.

[bkoenig]

Yep, just make sure the stock matches the tube.  Mil-spec is a little beefier I think, but in real life I doubt if any of us would ever abuse a gun to the point where a commercial one would fail.

[Brian]

Here's a couple of sites that talk about the differences:

http://www.carolinashootersforum.com/showthread.php?t=97170

Basically the easiest way to determine the difference between the two is the 5 degree sland on the back of commercial tubes as opposed to the straight style of the Mil-spec. I've used both styles in regular shooting and strenuous applications and I've never noticed the difference during use.

If you want good dimensional info (assuming in spec):
Mil-Spec
diameter 1.148"

Commercial
diameter 1.168"

http://www.ar15fornoobs.com/mil-spec-vs-commercial-spec-buffer-tubes

[altheman2]

Alright Thanks guys! I was getting a little confused