Adjustable gas block assembly for a gas operated semi-automatic firearm

Abstract

Adjustable gas block assemblies for gas-operated firearms are disclosed along with modes of operation and methods of use. In certain aspects, gas blocks having a vent opening arranged to receive a vent plug are disclosed, the vent plug having an opening along a length thereof to vent high-pressure gas from the gas block. Kits containing multiple vent plugs and, in some instances, gas blocks are also disclosed.

1 . A method of tuning the gas block assembly of  claim 4 , comprising:
 firing a cartridge in the firearm with the gas block assembly having the vent plug, which is a first vent plug, positioned within the vent opening;   determining whether the firearm properly extracted and ejected the cartridge and chambered a new cartridge or locked a bolt of the firearm in an open configuration;   replacing the first vent plug of the gas block assembly with a second vent plug having an opening extending along a length thereof, wherein the opening of the first vent plug has a different hydraulic diameter than the opening of the second vent plug; and   firing a cartridge in the firearm with the gas block assembly having the second vent plug positioned within the vent opening.   
     
     
         2 . The method of  claim 1 , wherein the opening of the second vent plug has a smaller hydraulic diameter than the opening of the first vent plug. 
     
     
         3 . The method of  claim 1 , wherein the opening of the second vent plug has a larger hydraulic diameter than the opening of the first vent plug. 
     
     
         4 . A gas block assembly for a firearm, comprising:
 a gas block defining a barrel opening, a gas tube opening, a passageway extending from the barrel opening to the gas tube opening, and a vent opening intersecting the passageway; and   a vent plug received within the vent opening;   wherein the vent plug has an opening extending along a length of the vent plug and in communication with the passageway so that high-pressure gas communicating with the passageway can pass through the opening in the vent plug and out of the gas block assembly.   
     
     
         5 . The gas block assembly of  claim 4 , wherein the vent plug is removably received within the vent opening. 
     
     
         6 . The gas block assembly of  claim 4 , wherein the vent plug is threadably received within the vent opening. 
     
     
         7 . The gas block assembly of  claim 4 , wherein the vent opening is positioned between the gas tube opening and the barrel opening. 
     
     
         8 . The gas block assembly of  claim 4 , wherein the vent opening extends from a forward surface of the gas block rearward to the passageway and wherein the gas tube opening extends from a rearward surface of the gas block forwardly to the passageway. 
     
     
         9 . The gas block assembly of  claim 4 , wherein the vent plug has a length sufficient to extend at least partially into the passageway when received within the vent opening. 
     
     
         10 . The gas block assembly of  claim 4 , wherein the vent opening has a first cross-sectional dimension adjacent an outer surface of the gas block and a second cross-sectional dimension adjacent the passageway and intermediate the passageway and the first cross-sectional dimension; and
 wherein the second cross-sectional dimension is smaller than the first cross-sectional dimension.   
     
     
         11 . The gas block assembly of  claim 10 , wherein the vent plug has a first end matching the first cross-sectional dimension and a second end matching the second cross-sectional dimension. 
     
     
         12 . The gas block assembly of  claim 10 , wherein a portion of the vent opening having the first cross-sectional dimension of the vent opening is a threaded portion and a portion of the vent opening having the second cross-sectional dimension is free of threads. 
     
     
         13 . An upper assembly for a firearm, comprising:
 the gas block assembly of  claim 4 ;   an upper receiver; and   a barrel attached to the upper receiver;   wherein the gas block assembly is attached to the barrel.   
     
     
         14 . A firearm, comprising:
 the upper assembly of  claim 13  attached to a lower assembly.   
     
     
         15 . A kit, comprising:
 the gas block assembly of  claim 4  wherein the vent plug is a first vent plug; and   a second vent plug for the gas block;
 wherein the second vent plug has a length. 
   
     
     
         16 . The kit of  claim 15 , wherein:
 the opening of the first vent plug has a minimum cross-sectional dimension; and   the second vent plug has an orifice extending through the length thereof, the orifice of the second vent plug having a minimum cross-sectional dimension less than that of the orifice opening of the first vent plug.   
     
     
         17 . The kit of  claim 15 , wherein:
 the second vent plug is free of an orifice extending through the length thereof.   
     
     
         18 . The kit of  claim 15 , wherein:
 the length of one of the first or second vent plugs is greater than the other   
     
     
         19 . The kit of  claim 18 , wherein:
 the longer vent plug is free of an orifice.   
     
     
         20 . (canceled)