Jul 29, 2025

US12372338 - Method of reducing gun barrel heating

A cartridge includes a bullet on which there is formed a coating. At least an upper layer of the coating is porous and comprises a thermoset polymer and a filler. The filler may be a dry film lubricant. The cartridge may be used in a gun of the type that has a rifled barrel. A rifled barrel has a bore diameter and a groove diameter. The bullet may have a metal diameter that is less than the groove diameter but slightly greater than the bore diameter. The coated bullet may have a diameter that is greater than or equal to the groove diameter. When fired, the bullet produces less barrel friction and heating than a conventional bullet. The velocity of the coated bullets is greater and the velocity distribution is more narrow compared to uncoated bullets.

Inventors: Andrew W. Suman
Filing date: 2023-01-26

firearmammunitionbulletcoatingbarrel

This patent describes a cartridge featuring a bullet coated with a porous thermoset polymer and filler, designed to reduce friction and heating in rifled gun barrels. The coated bullet achieves higher velocity and a more consistent velocity distribution compared to traditional uncoated bullets.

Claim 1

A loaded gun, comprising: a gun loaded with a bullet; wherein the bullet has a metal core and a coating on the metal core; the coating comprising a thermoset polymer and a filler; the gun has a barrel with rifling that includes grooves and lands; the barrel has a bore diameter and a groove diameter; and the metal core has a diameter less than the groove diameter. a gun loaded with a bullet; wherein the bullet has a metal core and a coating on the metal core; the coating comprising a thermoset polymer and a filler; the gun has a barrel with rifling that includes grooves and lands; the barrel has a bore diameter and a groove diameter; and the metal core has a diameter less than the groove diameter.

Google Patents

https://patents.google.com/patent/US12372338

USPTO PDF

https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/12372338