Description Rifle Service Pak – Contains 1 each ejector spring, extractor spring, hammer spring, extra power recoil spring, safety plunger spring, sear spring, magazine catch spring and slide stop spring. Note: The US M1 Carbine is the original GI carbine. If your rifle has a single recoil spring it is a US model. If your gun has dual recoil springs you have a Universal Arms model.
