Abstract: A double shoulder angle firearm cartridge for AR-15, bolt action rifles, pistols, and any other firearm includes a firearm cartridge comprising a case that holds a primer, powder, and bullet. The case is defined by a case head forming a rim and an extractor groove, a body section extending from the case head, at least two shoulder angles extending from the body section, and a neck section extending from the shoulder angles. The shoulder is defined by at least two angles tapering into each other in an integral configuration. The first angle is 30°; and the second angle being a 17° 30? shoulder angle, substantially the same as the 7.62×39 Russian round. The diameter of the case is approximately 0.447 inches. The length of the case is approximately 1.530 inches.