Reducing the Size of a Gas Port of a Gas Operated Firearm

Abstract

Usually when a gas port of a gas operated firearm is oversized or eroded, or a firearm is being modified, for example, to use a suppressor, the barrel often has to be replaced with a barrel having a smaller sized gas port; this is particularly wasteful when the original barrel is otherwise serviceable for many more thousands of rounds. The present invention reduces the need to replace the barrel.

What is claimed: 
     
         1 . An apparatus for reducing the size of a gas port of a gas operated firearm, the apparatus comprising:
 a barrel wall ( 200   a ) with outer ( 220   a ) and inner ( 240   a ) surfaces,   a modified gas port ( 260   a ) is located between the outer ( 220   a ) and inner ( 240   a ) surfaces, the modified gas port ( 260   a ) comprises an inverted female top hat configuration ( 280   a ) and a worn first bore ( 360   a ), the inverted female top hat configuration ( 280   a ) comprises a third bore ( 500   a ) and a fourth bore ( 520   a ),   a male gas port insert ( 420   a ) is located in the inverted female top hat configuration ( 280   a ) such that the male gas port insert ( 420   a ) occupies at least a portion of the third bore ( 500   a ) and at least a portion of the fourth bore ( 520   a ), the male gas port insert ( 420   a ) having a second bore ( 440   a ) therethrough,   a flared portion ( 460   a ) located at a first opposite end ( 445   a ) of the second bore ( 440   a ), the flared portion ( 460   a ) is in fluid communication with the second bore ( 440   a ) and the worn first bore ( 360   a ),   wherein the worn first bore ( 360   a ) defines a first diameter ( 400   a ) of at least a portion of the worn first bore ( 360   a ),   wherein the second bore ( 440   a ) defines a second diameter ( 455   a ) of at least a portion of the second bore ( 440   a ), and   wherein the second diameter ( 455   a ) is less than the first diameter ( 400   a ).   
     
     
         2 . The apparatus of  claim 1 ,
 wherein the flared portion ( 460   a ) defines a maximum diameter ( 465   a ), and   wherein the maximum diameter ( 465   a ) is equal to the first diameter ( 400   a ) of at least a portion of the worn first bore ( 360   a ).   
     
     
         3 . The apparatus of  claim 1 ,
 wherein the male gas port insert ( 420   a ) defines a stem ( 595   a ), the stem ( 595   a ) having a diameter ( 597   a ) of at least a portion of the stem ( 595   a ),   wherein the flared portion ( 460   a ) defines a maximum diameter ( 465   a ),   wherein the maximum diameter ( 465   a ) is greater than the first diameter ( 400   a ) of at least a portion of the worn first bore ( 360   a ), and   wherein the maximum diameter ( 465   a ) is less than the diameter ( 597   a ) of the stem ( 595   a ).   
     
     
         4 . The apparatus of  claim 1 , wherein the male gas port insert ( 420   a ) is press fitted into the inverted female top hat configuration ( 280   a ). 
     
     
         5 . The apparatus of  claim 1 , wherein the male gas port insert ( 420   a ) has a T-shaped cross section ( 480   a ) to complement the shape of the inverted female top hat configuration ( 280   a ). 
     
     
         6 . An apparatus for reducing the size of a gas port of a gas operated firearm, the apparatus comprising:
 a barrel wall ( 200   b ) with outer ( 220   b ) and inner ( 240   b ) surfaces,   a modified gas port ( 260   b ) is located between the outer ( 220   b ) and inner ( 240   b ) surfaces, the modified gas port ( 260   b ) comprises an inverted female top hat configuration ( 280   b ) and a worn first bore ( 360   b ), the inverted female top hat configuration ( 280   b ) comprises a third bore ( 500   b ) and a fourth bore ( 520   b ),   a male gas port insert ( 420   b ) is located in the inverted female top hat configuration ( 280   b ) such that the male gas port insert ( 420   b ) occupies at least a portion of the third bore ( 500   b ) and at least a portion of the fourth bore ( 520   b ), the male gas port insert ( 420   b ) having a second bore ( 440   b ) therethrough such that the second ( 440   b ) and first ( 360   b ) bores extend between the outer ( 220   b ) and inner ( 240   b ) surfaces,   wherein the worn first bore ( 360   b ) defines a first diameter ( 400   b ) of at least a portion of the worn first bore ( 360   b ),   wherein the second bore ( 440   b ) defines a second diameter ( 455   b ) of at least a portion of the second bore ( 440   b ),   wherein the second diameter ( 455   b ) is less than the first diameter ( 400   b ), and   wherein a flared portion ( 460   a ) is not located at a first opposite end ( 445   b ) of the second bore ( 440   b ).   
     
     
         7 . The apparatus of  claim 6 , wherein the male gas port insert ( 420   b ) is press fitted into the inverted female top hat configuration ( 280   b ). 
     
     
         8 . The apparatus of  claim 6 , wherein the male gas port insert ( 420   b ) has a T-shaped cross section ( 480   b ) to complement the shape of the female top hat configuration ( 280   b ). 
     
     
         9 . An apparatus for reducing the size of a gas port of a gas operated firearm, the apparatus comprising:
 a barrel wall ( 200   t ) with outer ( 220   t ) and inner ( 240   t ) surfaces,   a modified gas port ( 260   t ) is located between the outer ( 220   t ) and inner ( 240   t ) surfaces, the modified gas port ( 260   t ) comprises an inverted female top hat configuration ( 280   t ) and a worn first bore ( 360   t ), the inverted female top hat configuration ( 280   t ) comprises a third bore ( 500   t ) and a fourth bore ( 520   t ),   a male gas port insert ( 420   t ) screwed into the inverted female top hat configuration ( 280   t ) such that the male gas port insert ( 420   t ) occupies at least a portion of the third bore ( 500   t ) and at least a portion of the fourth ( 520   t ) bore, the male gas port insert ( 420   t ) having a second bore ( 440   t ) therethrough,   a flared portion ( 460   t ) located at a first opposite end ( 445   t ) of the second bore ( 440   t ), the flared portion ( 460   t ) is in fluid communication with the second bore  440   t  and the worn first bore  360   t,      wherein the worn first bore ( 360   t ) defines a first diameter ( 400   t ) of at least a portion of the worn first bore ( 360   t ),   wherein the second bore ( 440   t ) defines a second diameter ( 455   t ) of at least a portion of the second bore ( 440   t ),   wherein the second diameter ( 455   t ) is less than the first diameter ( 400   t ).   
     
     
         10 . The apparatus of  claim 9 , wherein the male gas port insert ( 420   t ) defines a stem ( 595   t ), wherein an external thread ( 600   t ) extends at least partway around stem ( 595   t ), and wherein a complementary internal thread ( 620   t ) extends at least partway around the fourth bore ( 520   t ) of the inverted female top hat configuration ( 280   t ). 
     
     
         11 . The apparatus of  claim 9 ,
 wherein the male gas port insert ( 420   t ) defines a stem ( 595   t ), the stem ( 595   t ) having a diameter ( 597   t ) of at least a portion of the stem ( 595   t ),   wherein the flared portion ( 460   t ) defines a maximum diameter ( 465   t ), and   wherein the maximum diameter ( 465   t ) is equal to the first diameter ( 400   t ).   
     
     
         12 . The apparatus of  claim 9 ,
 wherein the male gas port insert ( 420   t ) defines a stem ( 595   t ), the stem ( 595   t ) having a diameter ( 597   t ) of at least a portion of the stem ( 595   t ),   wherein the flared portion ( 460   t ) defines a maximum diameter ( 465   t ),   wherein the maximum diameter ( 465   t ) is greater than the first diameter ( 400   t ) of at least a portion of the worn first bore ( 360   t ), and   wherein the maximum diameter ( 465   t ) is less than the diameter ( 597   t ) of the stem ( 595   t ).