If possible, try to get a left-handed upper receiver that has free-floating rails. Which will provide your AR-15 with greater accuracy. Bolt Carrier Group The AR-15 bolt carrier group (BCG) is the heart of your rifle and the component that makes the rifle functional. The bolt carrier ...
Real 1,2 , Patrick McMillen 3, Madeleine Oudin 4, Michael Levin 3 and María Roqué 1,5,* 1 Institute of Histology and Embryology, National Council of Scientific and Technological Research (CONICET), Parque General San Martin, Mendoza 5500, Argentina; smasuelli@mendoza-conicet.gob.ar (S.M...