Your Browser is OutdatedDon't understand difference between commercial and Mil-Spec stock? Also says adjustible but use standard Mil-Spec tube, do use long tube or carbine? — 2 Answers
The significant difference between the mil-spec and commercial AR-15 buffer tubes is the outer diameter of the stock-end, which will also determine the type of buttstock you buy.
At the buttstock end, the commercial buffer tube is .02” wider than the mil-specific buffer tube—1.168" vs. 1.148" diameter respectively. But at the receiver end, the mil-spec tube diameters are .015” wider than commercial spec tubes at 1.170” (including the height of the threads) vs commercial tubes which are 1.185".
Commercial sized buffer tubes were one of the many abominations that arose from the’94 AWB. Basically Colt, DPMS & the big names at that time were forced to adopt the commercial tube, among many other useless mods.But after ‘04 nobody serious uses them anymore unless forced! & both are carbine length, but it’s the O.D. that’s different.