. I have set it into a number of various firearms with various calibers starting from seven.62, 9mm, 5.fifty six, ect. Its ran flawlessly in each one. I did not have to swap buffers or springs or everything. Just flip to third position and he or she's prepared to go.. https://rare-breed-frt14096.tribunablog.com/details-fiction-and-rare-breed-trigger-50626187