"milspec" isn't always the "best spec" --I will agree that proof knows what it is doing when it comes to space craft and fighter jets, they in fact do hold a contract with the DOD for the barrels used on the barret MRAD-- but remember the MIL has different standards than the private sector when it comes to longevity-- you or I may want the barrel to last for 100+ years with low round counts-- the mil has totally different criteria for choosing manufactures and specifications-- they would probably be happy if a barrel lasted a few years with the round counts they go through--as others have said, barrels are consumables especially to the MIL
I'm not knocking polymers, CF barrels or proof, I'm just saying that without more knowledge of materials used and longevity testing there is no real way to know how long a CF barrel would last-- though I think they would last quite a long time. I would love to see a side by side longevity test done of a proof CF and SS barrel, but where would you start? how could you make the 2 "equals"
as we know marketing hype is used in every industry-- I bought a glass strand/CF reinforced polymer AR lower from a company that claims they have a background in aircraft design and manufacturing, they even brought an experimental aircraft to market-- the 8 oz. stripped lower fell less than 18" and it broke-- gotta use the right materials for the job with the right dimensions