a) a barrel having front and rear ends and a top and bottom, a chamber for receiving a shell being disposed on said rear end, said chamber having top and bottom portions;

b) a breech block being disposed on the firearm contiguous to said rear end of said barrel, said breech block having top and bottom ends, first and second sides and front and rear surfaces, said breech block having a first hole therein, said first hole being longitudinally aligned with said chamber, a firing pin being disposed in said first hole, said firing pin having front and rear ends, a firing pin spring being disposed on said firing pin to bias said firing pin rearwardly away from said chamber;

c) a receiver being disposed adjacent said rear of said breech block for containing portions of the apparatus, said receiver having a top surface;

d) an action bar having front and rear ends, first and second sides and top and bottom surfaces being slidably disposed in said receiver of a firearm so that said front end of said action bar can contact said rear end of said firing pin, wherein the central axis of said action bar is aligned with the central axis of said firing pin, said action bar having a transverse slot therein and a notch thereon, said slot having front and rear surfaces and said notch being disposed on said bottom of said action bar, wherein said action bar has an uncocked position and a cocked position;

e) a main spring having first and second ends being disposed around said action bar, wherein said action bar is biased toward said firing pin by said main spring when said action bar is in said cocked position;

f) a cocking piece being slidably disposed on said receiver of the firearm so that said cocking piece can be moved back and forth between a first position wherein said action bar is uncocked and a second position wherein said action bar is cocked, wherein said cocking piece is adapted for connection to said action bar so that said action bar can be moved rearwardly to said cocked position;

g) a trigger being pivotally disposed in said receiver adjacent to and beneath said action bar, said trigger having top and bottom ends and front and rear surfaces, a tab being disposed on said top end of said rear surface of said trigger, wherein said bottom of said trigger is adapted for being held by a finger of a user; and,

h) a sear having front and rear ends and top and bottom surfaces being pivotally disposed in said receiver, wherein when said action bar is moved rearwardly to said cocked position in response to said cocking piece, said sear being adapted to contact said action bar so as to secure said action bar in said cocked position, wherein when said bottom end of said trigger is pulled to the rear by a user said trigger is adapted to move said sear to a position where said action bar is released from said sear and said action bar is driven forward in response to said main spring so that said front end of said action bar strikes said rear end of said firing pin thereby driving said front end of said firing pin into the primer of a shell so that the firearm is thereby fired.