Rifling profile for firearms
A firearm barrel is provided having a body defining an outer surface and a bore. The bore may define a rifling profile along at least a portion of a length of the barrel. The rifling profile may define a cross-sectional profile perpendicular to the length of the barrel at a location along the length of the barrel. The cross-sectional profile may include a plurality of arcuate portions and a plurality of linear portions. The cross-sectional profile may define a cross-sectional area defined by a Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) standard rifling profile. Various embodiments may include firearms, assemblies, components, and methods associated with such firearms and firearm barrels.
1. A firearm barrel defining a center axis and configured to receive a bullet having a caliber, the firearm barrel comprising:
a body defining an outer surface and a bore,
wherein the bore defines a rifling profile along at least a portion of a length of the firearm barrel,
wherein the rifling profile defines a cross-sectional profile perpendicular to the length of the firearm barrel at a location along the length of the firearm barrel,
wherein the cross-sectional profile comprises a plurality of arcuate portions and a plurality of linear portions, and
wherein the cross-sectional profile defines a cross-sectional area defined by a Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) standard rifling profile for the caliber.
2. The firearm barrel of claim 1 , wherein at least a portion of the bore, including a first portion of the bore at the location, is coated with a coating.
3. The firearm barrel of claim 2 , wherein the coating comprises chrome.
4. The firearm barrel of claim 1 , wherein the plurality of arcuate portions and the plurality of linear portions comprise alternating arcuate portions and linear portions.
5. The firearm barrel of claim 4 , wherein the plurality of arcuate portions and the plurality of linear portions comprise an equal number of the arcuate portions and the linear portions.
6. The firearm barrel of claim 5 , wherein the plurality of arcuate portions and the plurality of linear portions comprise six arcuate portions and six linear portions.
7. The firearm barrel of claim 1 , wherein a diameter of the bore spanning two opposite arcuate portions of the plurality of arcuate portions is defined as a diameter of a projectile for which the firearm barrel is sized.
8. The firearm barrel of claim 1 , wherein the linear portions define a first radius at their closest point to the center axis at the location and the arcuate portions define a second radius to the center axis at the location, wherein the first radius is 97.5% to 97.8% of the second radius.
9. The firearm barrel of claim 8 , wherein the rifling profile comprises an even number of the linear portions and an even number of the arcuate portions.
10. The firearm barrel of claim 1 , wherein the linear portions define a first diameter at their closest point to the center axis at the location and the arcuate portions define a second diameter to the center axis at the location, wherein the firearm barrel is configured to receive a .277 Fury or 6.8 mm caliber bullet, wherein the first diameter is 0.270 and the second diameter is 0.277.
11. The firearm barrel of claim 1 , wherein the firearm barrel is sized to fire M855 or M193 cartridges.
12. The firearm barrel of claim 1 , wherein the cross-sectional area is 0.0388 square inches.
13. The firearm barrel of claim 1 , wherein the cross-sectional profile comprises at least three and up to five arcuate portions and at least three and up to five linear portions.
14. The firearm barrel of claim 1 , wherein the cross-sectional profile comprises three arcuate portions and three linear portions.
15. The firearm barrel of claim 1 , wherein the bullet that the firearm barrel is configured to receive is a bullet from a high pressure cartridge.
16. A firearm comprising:
a receiver;
a trigger assembly;
a buttstock; and
a barrel defining a center axis and configured to receive a bullet having a caliber, the barrel comprising:
a body defining an outer surface and a bore,
wherein the bore defines a rifling profile along at least a portion of a length of the barrel,
wherein the rifling profile defines a cross-sectional profile perpendicular to the length of the barrel at a location along the length of the barrel,
wherein the cross-sectional profile comprises a plurality of arcuate portions and a plurality of linear portions, and
wherein the cross-sectional profile defines a cross-sectional area defined by a Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) standard rifling profile for the caliber.
17. The firearm of claim 16 , wherein the plurality of arcuate portions and the plurality of linear portions comprise an equal number of the arcuate portions and the linear portions.
18. The firearm of claim 17 , wherein the plurality of arcuate portions and the plurality of linear portions comprise six arcuate portions and six linear portions.
19. The firearm of claim 16 , wherein the linear portions define a first radius at their closest point to the center axis at the location and the arcuate portions define a second radius to the center axis at the location, wherein the first radius is 97.5% to 97.8% of the second radius.
20. The firearm of claim 19 , wherein the rifling profile comprises an even number of the linear portions and an even number of the arcuate portions.