Actual, the threads are exactly the same dia and pitch. Commercial is a larger tube and has the slanted rear - commercial stock will go over a mil spec tube way to loose, but a mil stock will not side on a commercial tube.
Originally Posted by BigfootHunter
The main difference between commercial/milspec is the threads on the tube, if they're proud of the tube (thicker than the tube) most likely mil spec, if they're cut INTO the tube (same diameter as the tube) then it's probably commercial.
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