Following a shoulder replacement and recovery, the implants are very stable.  However, one must remember that the articulation is that of a metal “ball” on a plastic socket.  Activities that increase compressive and shear force on the artificial joint can lead to accelerated plastic wear of the socket.  Shooting high caliber rifles and shotguns that cause a big recoil, depending on the size of the person and shooting style, can lead to accelerated wear and early loosening.  It would be best to use a small caliber rifle or shotgun to minimize the increased shear forces.