. I have set it into several various firearms with different calibers starting from 7.sixty two, 9mm, five.56, ect. Its ran flawlessly in every one. I didn't have to swap buffers or springs or anything at all. Just flip to 3rd posture and he or she's able to go.. Thanks https://frttriggers84947.webbuzzfeed.com/36730056/top-latest-five-rare-breed-frt-urban-news