US Patent 12111140 Projectile and firearm system

A cartridge is disclosed with a casing and a projectile, wherein external ballistic stability is provided by a center of pressure of the projectile being rearward of a center of mass of the projectile. The projectile includes flight control surfaces that cooperate with the bore of a barrel without requiring rifling or sabots. The projectile can include fin configurations that cooperate with the bore to form a gas check.