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.