Ruger AR556 450BM upper receiver complete. Used with some wear however not very many rounds through it. Silencerco ASR muzzle brake but it still kicks like a mule. Pmags have 3D printed followers and should only be loaded with hollow point ammunition due to the internal spine within the mag body that will interfere with pointed bullets. Metal mags have no problem with all bullet types. Upper can be used with standard AR lower receivers. I also have 450BM reloading components