Firearm

Abstract

An upper receiver is disclosed. The firearm contains a bolt carrier assembly positioned within the upper receiver, a recoil spring guide rod, wherein the bolt carrier assembly is configured to slide along the recoil spring guide rod between a locked position and an unlocked position, and a first recoil spring, wherein the recoil spring guide rod is positioned within the first recoil spring.

1 - 15 . (canceled) 
     
     
         16 . An end plate comprising:
 a first surface;   a second surface positioned opposite the first surface; and   a first outer threaded surface configured to mate with an upwardly extending lobe of a lower receiver.   
     
     
         17 . The end plate of  claim 16  further comprising a second outer threaded surface configured to mate with another end plate. 
     
     
         18 . The end plate of  claim 17  further comprising one or more slots configured to accommodate detent pin associated with the upwardly extending lobe. 
     
     
         19 . The end plate of  claim 17  further comprising an aperture configured to accommodate a tool. 
     
     
         20 . An end plate comprising:
 a first surface;   a second surface positioned opposite the first surface; and   a threaded aperture configured to mate with an outer threaded surface of another plate.   
     
     
         21 . The end plate of  claim 20  further comprising one or more rails. 
     
     
         22 . An assembly comprising:
 a first end plate comprising a first outer threaded surface configured to mate with an upwardly extending lobe of a lower receiver and a second outer threaded surface.   
     
     
         23 . The assembly of  claim 22 , further comprising a second end plate comprising a threaded aperture configured to mate with the second outer threaded surface. 
     
     
         24 . The assembly of  claim 23 , wherein the first end plate further comprises one or more slots configured to accommodate detent pin associated with the upwardly extending lobe. 
     
     
         25 . The assembly of  claim 23  wherein the first end plate further comprises an aperture configured to accommodate a tool. 
     
     
         26 . The assembly of  claim 23  wherein the second end plate further comprises one or more rails.