How to tell which tube?

As far as I know Armalite is commercial spec. Colt, Stag, LMT use milspec.

There is a couple of mm difference between the thicknesses, milspec being slightly smaller.

Best way to figure it out is to measure the buffer tube on your stock with a dial or digital caliper. If it is 1.14" it is mil-spec. If it is 1.17" it is commercial. Also, the mil-spec tubes are square at the back end while the commercial tubes are slightly angled.

rob
 
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Excellent explanation robstar. You know your stuff, but i'm not 100% sure on that square/angled statement you made.
 
not all Colt's are Milspec.

I have a Colt Sporter AR and it has a commercial spec tube.

That being said...does anyone know where I can get a Mil-spec buffer tube assembly? I have a Magpul CTR stock that I can't use on my commerical tube.

I've tried all of the usual suspects but I can't find one.
 
robstar said:
As far as I know Armalite is commercial spec. Colt, Stag, LMT use milspec.

There is a couple of mm difference between the thicknesses, milspec being slightly smaller.

Best way to figure it out is to measure the buffer tube on your stock with a dial or digital caliper. If it is 1.14" it is mil-spec. If it is 1.17" it is commercial. Also, the mil-spec tubes are square at the back end while the commercial tubes are slightly angled.

rob

Where exactly to measure? I put the calipers on it mid-way. and I get 1.150....?
 
Mil Spec Tube?

I have an Armalite, with a commercial tube. Is possible to remove the tube and replace it with a mil spec tube? or will it not fit on the lower receiver.

Thanks:D
 
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