choice Buffer spring Match your favorite weapon caliber.
Life needle Buffer spring It has a standard cartridge and an overall case shape, so it's like a fake cartridge. Some of them have a spring like shock absorber that absorbs the force produced by the impactor in the dry ball, thus facilitating batting practice without damaging any internal parts.
relieve Shotgun Here they are. 2 units
relieve Rifle Here they are. 3 units