7.62 x 39mm (CommonSKS, AK47, and AK47 clone ammunition), Spring Loaded Firing Pin, Dual Safety; Screw-on Barrel, Hairpin Safety or Screwlock "barrel lock" thumb nut so it won't loosen from vibration. Choice of two safeties, whichever the user prefers, 6mm Mount Threads, This unit is very versatile. Lots of BIG POWER. Used for Gator hunting, Shark fishing, big game fishing and spear fishing,. 303 Stainless Steel.