Rotatable firearm bolt assembly and firearms including the same

Abstract

Firearm bolt assemblies and firearms including the same are described. In embodiments the firearm bolt assemblies are configured to localize compressive forces applied during a transition from an initial position to a firing position to a first cam system on one side of the firearm bolt assembly, and to localize compressive forces applied during a transition from the firing position to the initial position to a second cam system another side of the firearm bolt assembly. Localizing the forces in that manner enables the use of a first cam system that is relatively robust compared to the second cam system.

What is claimed is: 
     
         1 . A firearm bolt assembly, comprising:
 a first side, a second side, a proximal end, and a distal end, the first side being substantially opposite the second side;   a bolt head;   a bolt body;   a first cam system defined by only a pair of single first complementary cam surfaces proximate the first side of the firearm bolt assembly, the bolt head comprising one of the pair of single first complementary cam surfaces, the bolt body comprising another of the pair of single first complementary cam surfaces; and   a second cam system defined by only a pair of single second complementary cam surfaces proximate the second side of the firearm bolt assembly, the bolt head comprising one of the pair of single second complementary cam surfaces, the bolt body comprising another of the pair of single second complementary cam surfaces.   
     
     
         2 . The firearm bolt assembly of  claim 1 , wherein:
 the firearm bolt assembly is movable from an initial position to a firing position by compression of the bolt body towards the proximal end, during which a predominant compression force is born by the first cam system; and   the firearm bolt assembly is movable from the firing position to the initial position by retraction of the bolt body away from the proximal end, during which a predominant compression force is born by the second cam system.   
     
     
         3 . The firearm bolt assembly of  claim 1 , wherein:
 one of the pair of single first complementary cam surfaces comprises a first helical cam surface and the other of the pair of single first complementary cam surfaces comprises second helical cam surface that is complementary to the first helical cam surface, such that when the firearm bolt assembly is moved from the initial position to the firing position interaction of the first and second helical cam surfaces causes the bolt head to twist, relative to the bolt body, in a first direction about an axis extending through the bolt head and the bolt body.