 An example proofing round for the .50 BMG (12.7 × 99 mm) is the "cartridge, caliber .50, test, high pressure, M1".This uses the standard-weight .50 BMG M1 round propellant (240 gr of WC860), but a bullet weighing 999 gr (+/- 11 gr).The M1 proof round gives a proofing pressure of ~65,000 psi, 11,000 psi (~17%) above the standard service pressure.