I had to put a lighter spring in my full sized M16 A2 clone nonetheless it ran good. Tried using all over again Along with the 11.five" Comando Colt upper. No dice. Ran five hundred rounds of wolf by means of it today. Didnt damage the spring at all. Even https://frttrigger88763.wikiexcerpt.com/3882679/not_known_facts_about_frt_15