Firearm with interchangeable parts

Abstract

A modernized firearm including interchangeable features.

1 - 20 . (canceled) 
     
     
         21 . A firearm, comprising:
 a first barrel associated with a first firearm model;   a barrel nut, wherein the first barrel is removably mated to the barrel nut for substituting the first barrel with a second barrel associated with a second firearm model;   a receiver associated with the first firearm model; and   a trunnion, an outer surface of the trunnion on each of a left side and a right side of the trunnion comprising a conical depression, two parallel vertically oriented elongated recesses disposed towards a front face of the trunnion and extending upwardly from a bottom of the trunnion, and a horizontally oriented elongated recess disposed behind the two vertically oriented elongated recesses and above the conical depression, the horizontally oriented elongated recess extending forwardly from a rear face of the trunnion.   
     
     
         22 . The firearm of  claim 21 , further comprising a bolt block, the bolt block comprising a set screw for adjusting a position of the bolt block to configure the firearm for use with a plurality of types of ammunition. 
     
     
         23 . The firearm of  claim 22 , wherein the bolt block is disposed behind a bolt, and wherein the set screw is configured for adjusting a head space between the bolt and a round of ammunition in the firearm. 
     
     
         24 . The firearm of  claim 21 , wherein the firearm is a semi-automatic tilting-bolt rifle. 
     
     
         25 . The firearm of  claim 21 , wherein the receiver comprises a magazine holder, and wherein the firearm further comprises a magazine retention block, the magazine retention block configured to couple the magazine to the magazine holder. 
     
     
         26 . The firearm arm of  claim 21 , further comprising a charging handle and a gas piston, wherein the charging handle is coupled to the gas piston. 
     
     
         27 . A firearm, comprising:
 a first magazine associated with a first firearm model;   a receiver associated with the first firearm model and comprising a magazine holder for removably coupling the first magazine for substituting the first magazine with a second magazine associated with a second firearm model; and   a magazine retention block configured to couple at least the first magazine to the magazine holder, the magazine retention block comprising a top surface, a tapered portion that tapers towards a bottom of the magazine retention block, a front surface having a groove, a magazine catch, and a magazine catch release.   
     
     
         28 . The firearm of  claim 27 , further comprising a bolt block supported by a pin, and wherein the top surface of the magazine retention block abuts the pin. 
     
     
         29 . The firearm of  claim 27 , wherein the magazine retention block comprises a pin hole for receiving a pin, the pin being configured to couple a trigger assembly to the receiver. 
     
     
         30 . The firearm of  claim 27 , further comprising a trunnion, an outer surface of the trunnion on each of a left side and a right side of the trunnion comprising a conical depression, two parallel vertically oriented elongated recesses disposed towards a front face of the trunnion and extending upwardly from a bottom of the trunnion, and a horizontally oriented elongated recess disposed behind the two vertically oriented elongated recesses and above the conical depression, the horizontally oriented elongated recess extending forwardly from a rear face of the trunnion. 
     
     
         31 . The firearm of  claim 27 , wherein the firearm is a semi-automatic tilting-bolt rifle. 
     
     
         32 . The firearm of  claim 27 , further comprising a bolt block, the bolt block comprising a set screw for adjusting a position of the bolt block to configure the firearm for use with a plurality of types of ammunition. 
     
     
         33 . The firearm of  claim 32 , wherein the bolt block is disposed behind a bolt, and wherein the set screw is configured for adjusting a head space between the bolt and a round of ammunition in the firearm. 
     
     
         34 . The firearm of  claim 27 , further comprising a charging handle and a gas piston, wherein the charging handle is coupled to the gas piston. 
     
     
         35 . A magazine retention block for a firearm comprising:
 a top surface;   a tapered portion that tapers towards a bottom of the magazine retention block;   a front surface having a groove;   a magazine catch; and   a magazine catch release, wherein the magazine catch is configured to couple a magazine to a magazine holder.