FRT 15 NO FURTHER A MYSTERY

I had to set a lighter spring in my whole sized M16 A2 clone nonetheless it ran wonderful. Attempted all over again Along with the 11.five" Comando Colt upper. No dice. Ran 500 rounds of wolf through it now. Didnt harm the spring in the slightest degree.For that matter, I think when challenged in courtroom, not all of rare breeds patents will hold