Buffalo Bore Ammunition 19A/20: Buffalo Bore\'s 357 mag. ammo adds more power than ever before to the 357 mag. This ammo is safe to shoot in ANY all-steel 357 revolver, including J frames. This ammo is no harder on your gun than any other normal 357 ammo. This ammo is safe providing the gun is in safe condition for use with any normal 357 ammo. This ammo is not recommended to be fired in super light alloy revolvers the recoil is severe enough to cause crimp jump, but the ammo itself wont hurt these super lightweight revolvers.