Ballistic zinc alloys, firearm projectiles, and firearm ammunition containing the same

Abstract

Firearm cartridges, firearm projectiles, and/or projectile components formed at least in part from a disclosed ballistic zinc alloy. These ballistic zinc alloys overcome shortcomings of other lead substitutes for firearm projectiles, including Zamak alloys and other conventional zinc alloys. In some embodiments, and as compared to a firearm projectile formed from a conventional zinc alloy, a ballistic zinc alloy firearm projectile has at least one of an increased ductility, an increased frangibility, and/or a decreased tendency to smear or gall within a rifled firearm barrel. In some embodiments, the ballistic zinc alloy is a zinc-aluminum alloy that includes additional alloy components that collectively enhance the properties of the ballistic zinc alloy for use in firearm projectiles.

1 . A firearm cartridge, comprising:
 a casing adapted to be received into a firearm;   a primer and a propellant within the casing; and   a firearm projectile at least partially received into the casing, wherein the firearm projectile is a cast unitary bullet that is at least substantially formed from a ballistic zinc alloy with a hardness of less than 60 BHN and wherein the ballistic zinc alloy comprises:
 90%-98% Zn; and 
 2.0%-4.1% Al. 
   
     
     
         2 . The firearm cartridge of  claim 1 , wherein the ballistic zinc alloy further comprises a combination of at least one of magnesium, copper, iron, and nickel. 
     
     
         3 . The firearm cartridge of  claim 1 , wherein the firearm projectile is a mushrooming bullet that is configured to mushroom upon impact with a target. 
     
     
         4 . The firearm cartridge of  claim 3 , wherein the mushrooming bullet has a diameter and wherein the mushrooming bullet is configured to expand in diameter by at least 25% upon impact with the target. 
     
     
         5 . The firearm cartridge of  claim 3 , wherein the ballistic zinc alloy of the mushrooming bullet has a percent elongation at fracture of at least 10%. 
     
     
         6 . The firearm cartridge of  claim 3 , wherein the mushrooming bullet includes a nose portion that consists essentially of the ballistic zinc alloy. 
     
     
         7 . The firearm cartridge of  claim 6 , wherein the mushrooming bullet includes a shank portion that consists essentially of materials other than the ballistic zinc alloy. 
     
     
         8 . The firearm cartridge of  claim 2 , wherein the ballistic zinc alloy comprises, by weight, one or more of at most 3.5% Al, at most 0.025% Mg, and at most 0.075% Fe. 
     
     
         9 . The firearm cartridge of  claim 8 , wherein the ballistic zinc alloy comprises, by weight:
 at most 4.0% Al;   at most 0.015% Mg;   at most 0.20% Cu;   at most 0.05% Fe;   0.005%-0.15% Ni; and   at least 90% Zn.   
     
     
         10 . The firearm cartridge of  claim 8 , wherein the ballistic zinc alloy comprises, by weight:
 2.45%-2.75% Al;   0.005%-0.02% Mg;   at most 0.25% Cu;   at most 0.075% Fe;   0%-0.15% Ni; and   at least 90% Zn.   
     
     
         11 . The firearm cartridge of  claim 8 , wherein the ballistic zinc alloy comprises, by weight:
 3.5%-4.3% Al;   0.005%-0.02% Mg;   at most 0.25% Cu;   at least 0.12% Fe;   0.005%-0.02% Ni; and   at least 90% Zn;   wherein the ballistic zinc alloy has a hardness of less than 40 BHN.   
     
     
         12 . The firearm cartridge of  claim 1 , wherein the firearm projectile is a frangible bullet that is configured to fragment into particles upon impact with a target. 
     
     
         13 . The firearm cartridge of  claim 12 , wherein the maximum size of the particles is 5 grains. 
     
     
         14 . The firearm cartridge of  claim 1 , wherein the firearm projectile includes a jacket that includes at least one of gilding metal and copper. 
     
     
         15 . A firearm cartridge, comprising:
 a casing adapted to be received into a firearm;   a primer and a propellant within the casing; and   a firearm projectile at least partially received into the casing, wherein the firearm projectile is a cast unitary bullet that is at least substantially formed from a ballistic zinc alloy that comprises, by weight:
 90-98% Zn; 
 at least 2.0% Al; and 
 one or more of at most 0.025% Mg, at most 0.075% Fe, at least 0.08% Mg, and at least 0.1% Fe. 
   
     
     
         16 . The firearm cartridge of  claim 15 , wherein the firearm cartridge is a shot shell and comprises a plurality of firearm projectiles, wherein the firearm projectiles are shot pellets. 
     
     
         17 . The firearm cartridge of  claim 15 , wherein the firearm projectile is at least one of a mushrooming bullet and a frangible bullet. 
     
     
         18 . The firearm cartridge of  claim 15 , wherein the firearm projectile includes a jacket that includes at least one of gilding metal and copper. 
     
     
         19 . A shot shell, comprising:
 a casing;   a wad within the casing;   a primer; and   a plurality of shot pellets received within the casing and separated from the primer and the propellant by the wad, wherein the plurality of shot pellets each is a cast unitary shot pellet that is at least substantially formed from a ballistic zinc alloy that comprises, by weight:   90-98% Zn; and   at least 2% Al.   
     
     
         20 . The shot shell of  claim 19 , wherein the ballistic zinc alloy further comprises a combination of at least one of Mg, Cu, FE, and Ni.