 The barrel then stops against a shoulder allowing the bolt carrier to continue rearward under the momentum imparted by the initial recoil stage.The rotating bolt, with eight locking lugs, would then unlock from the chamber as cam arrangement rotates and unlocks the bolt to continue the operating cycle.The Johnson rifle utilized a two-piece stock and a unique 10-round rotary magazine, designed to use the same 5-round stripper clips already in use by the M1903 Rifle.