Gun Barrel or Sleeve Therefor

Abstract

A gun barrel or sleeve for a gun barrel is provided. The invention includes staggered helical arrays of elliptical or oval blind cavities along the length of the gun barrel or sleeve. As a sleeve, the invention may be press-fit or force-fitted over a regular barrel or a barrel of reduced wall thickness. The cavities have radially extending orifices by which an angular width of an interior portion of a cavity is greater than an angular width of the orifice of that cavity, and a longitudinal dimension of the interior portion of that cavity is greater than a longitudinal dimension of the orifice of that cavity. The product may be produced by additive manufacturing, autofrettage, casting, forging or traditional CNC machining.

What is claimed is: 
     
         1 . A gun barrel comprising
 a longitudinal axis, an interior surface, an exterior surface, and   a plurality of angularly spaced apart cavities, with each of said cavities defining a longitudinal length and angular width and having an orifice piercing said exterior surface but not piercing said interior surface,   with each of said orifices having a longitudinal length less than said longitudinal length of its cavity, and having an angular width less than said angular width of its cavity.   
     
     
         2 . The gun barrel of  claim 1 , wherein at least one from among said plurality of cavities comprises a surface which is a convex floor. 
     
     
         3 . The gun barrel of  claim 2 , further comprising a concave surface radially spaced apart from said convex floor. 
     
     
         4 . The gun barrel of  claim 1  wherein said plurality of cavities is a first plurality of cavities, and further comprising a second plurality of cavities longitudinally spaced apart from said first plurality of cavities. 
     
     
         5 . The gun barrel of  claim 4 , wherein said second plurality of cavities is radially offset from said first plurality of cavities. 
     
     
         6 . The gun barrel of  claim 4 , further comprising a third plurality of cavities longitudinally spaced apart and radially offset from said second plurality of cavities, such that
 a first cavity from said first plurality of cavities,   a first cavity from said second plurality of cavities, and   a first cavity from said third plurality of cavities   
       define a helix along said longitudinal axis. 
     
     
         7 . A sleeve for a gun barrel comprising
 a longitudinal axis, an interior surface, an exterior surface, and   a plurality of angularly spaced apart cavities, with each of said cavities defining a longitudinal length and angular width and having an orifice piercing said exterior surface but not piercing said interior surface,   with each of said orifices having a longitudinal length less than said longitudinal length of its cavity, and having an angular width less than said angular width of its cavity.   
     
     
         8 . The sleeve of  claim 7 , wherein at least one from among said plurality of cavities comprises a surface which is a convex floor. 
     
     
         9 . The sleeve of  claim 8 , further comprising a concave surface radially spaced apart from said convex floor. 
     
     
         10 . The sleeve of  claim 7  wherein said plurality of cavities is a first plurality of cavities, and further comprising a second plurality of cavities longitudinally spaced apart from said first plurality of cavities. 
     
     
         11 . The sleeve of  claim 10 , wherein said second plurality of cavities is radially offset from said first plurality of cavities. 
     
     
         12 . The sleeve of  claim 10 , further comprising a third plurality of cavities longitudinally spaced apart and radially offset from said second plurality of cavities, such that
 a first cavity from said first plurality of cavities,   a first cavity from said second plurality of cavities, and   a first cavity from said third plurality of cavities   
       define a helix along said longitudinal axis.