Magazine-fed firearm

Abstract

A magazine-fed firearm has a frame, a barrel connected to the frame and chambered for a cartridge of a first selected specific type, the frame having a magazine well configured to receive a first magazine type configured to contain cartridges of the first selected specific type, the frame including a compatibility facility operable to facilitate operational presence in the magazine well of the first magazine type, and the compatibility facility operable to deny operational presence in the magazine well of a second magazine type configured to contain cartridges of a second specific type different from the first specific type and incompatible with the barrel. The first and second magazine types have a common dimensional characteristic compatible with the magazine well except for interface with the compatibility facility, such that without the compatibility facility, the first and second magazine types are otherwise compatible with the magazine well.

I claim: 
     
         1 . A magazine-fed firearm comprising:
 a frame;   a barrel connected to the frame and chambered for a cartridge of a first selected specific type;   the frame having a magazine well configured to receive a first magazine type configured to contain cartridges of the first selected specific type;   the frame including a compatibility facility operable to facilitate operational presence in the magazine well of the first magazine type; and   the compatibility facility operable to deny operational presence in the magazine well of a second magazine type configured to contain cartridges of a second specific type different from the first specific type and incompatible with the barrel.   
     
     
         2 . The magazine-fed firearm of  claim 1  wherein the first and second magazine types have a common dimensional characteristic compatible with the magazine well except for interface with the compatibility facility, such that without the compatibility facility, the first and second magazine types are otherwise compatible with the magazine well. 
     
     
         3 . The magazine-fed firearm of  claim 1  including a trigger guard connected to the frame and having the compatibility facility. 
     
     
         4 . The magazine-fed firearm of  claim 3  wherein the trigger guard is removably connected to the frame. 
     
     
         5 . The magazine-fed firearm of  claim 4  including a second trigger guard interchangeable with the trigger guard and having a second compatibility facility operable to facilitate an insertion in the magazine well of the second magazine type and to deny insertion in the magazine well of the first magazine type. 
     
     
         6 . The magazine-fed firearm of  claim 1  wherein the first and second magazine types each have different respective first and second upper rear elongated surface profiles configured to interface differently with the compatibility facility. 
     
     
         7 . The magazine-fed firearm of  claim 6  wherein the first and second upper rear elongated surface profiles have different cross-sectional profiles of protruding and recessed portions. 
     
     
         8 . The magazine-fed firearm of  claim 6  wherein the first magazine type defines a groove configured to closely receive a protrusion of the compatibility facility. 
     
     
         9 . The magazine-fed firearm of  claim 6  wherein the first magazine type defines a raised ridge configured to be received in a recess of the compatibility facility. 
     
     
         10 . The magazine-fed firearm of  claim 1  wherein the compatibility facility is proximate a lower rim of the magazine well. 
     
     
         11 . The magazine-fed firearm of  claim 1  wherein the compatibility facility is proximate a rear portion of the magazine well. 
     
     
         12 . The magazine-fed firearm of  claim 1  wherein the compatibility facility has a stop surface configured to enable only partial insertion of a first magazine type having a protrusion configured to engage the stop surface and prevent full insertion of the magazine into the magazine well, the stop surface configured to enable full insertion of a second magazine type lacking the protrusion. 
     
     
         13 . The magazine-fed firearm of  claim 12  including a trigger guard connected to the frame and wherein the stop surface is connected to the trigger guard. 
     
     
         14 . The magazine-fed firearm of  claim 12  wherein the stop surface is proximate a lower rim of the magazine well. 
     
     
         15 . The magazine-fed firearm of  claim 12  wherein the stop surface is proximate a rear portion of the magazine well. 
     
     
         16 . The magazine-fed firearm of  claim 12  wherein the protrusion is spaced apart from an upper end of the first magazine type, at an intermediate position along the length of the rear face of the first magazine type. 
     
     
         17 . The magazine-fed firearm of  claim 1  wherein the compatibility facility includes a magazine catch movably connected to the frame. 
     
     
         18 . The magazine-fed firearm of  claim 17  wherein the compatibility facility is operable to retain against extraction after insertion a first magazine type having a first catch engagement feature, and to enable extraction after insertion a second magazine type having a second catch engagement feature. 
     
     
         19 . The magazine-fed firearm of  claim 17  wherein the magazine catch is interchangeable with a second magazine catch operable to retain against extraction after insertion a second magazine type having a second catch engagement feature, and to enable extraction after insertion a first magazine type having a first catch engagement feature. 
     
     
         20 . The magazine-fed firearm of  claim 1  including a second compatibility facility operable to deny operational presence of the second magazine type.