I recently picked up a new buffer tube that I was told was a “mil-spec”, however, when I went to fit it in my BCM Mil-Spec stock, it was too big…the same with my Mil-Spec SOPMOD. Now I know that normally the rear of a Mil-Spec tube is 90 degrees from the ground and a commercial tube is usually angled down a bit. Also the mil-spec tube is slightly smaller around than the commercial…as I previously stated, this tube is too BIG for my mil-spec stocks, however, the rear of the tube is 90 degrees just like my other mil-spec receiver extensions…can anyone help me?
Since you tried a SOPMOD and a BCM mil-spec buttstock on there, I’m gonna go out on a limb and say you got hoodwinked. Its a commercial diameter tube.
Most gun shop jockeys are not as knowledgable as they tell you. They all think Bushmaster and DPMS are “mil-spec”, and "just as good as Colt. My advice is to order a tube direcly from Bravo Company or another reputable dealer.
yep… these guys probably have no clue that there’s a difference, and that it matters. so when you said, “is this milspec or commercial?” they just said, “it’s milspec,” because it looks like every RE they’ve ever seen.
Roger. But have you ever seen or heard of a commercial receiver extension having a square end as opposed to the standard angled end?
Yes Oly along with several other companies have sold commercial tubes with 90 degree ends over the years.
Yes, I have. Which is part of the reason why I will only buy my stuff from KNOWN vendors and won’t buy anything locally unless I have to.
Absolutely.
Go down to Harbor Freight and drop $10 on a set of cheap calipers. and measure the outside diameter of the tube. Every guy should have a set anyway.
1.147" = milspec
1.170" = commercial
Thats why I mostly sell and rarely buy unless its from a well known vendor.
If you don’t have a caliper, examine the threads.
If the threads are die cut and the same OD as the tube, it’s commercial. If the threads were roll formed and the tube OD is smaller, you can be certain it’s “mil spec”. No cheapskate manufacturer that I know of would bother with a more complicated process. I mean, they can’t even be arsed to stake carrier keys and castle nuts.
Thank you for the help.