The 10mm beats the .40 S&W by 270–300 ft/s (82–91 m/s) for comparable shot loads when utilizing accessible full power loads, instead of the "10mm FBI" level loads actually found in some ammo indexes. This outcome is because of the 10mm Auto's higher SAAMI pressure rating of 37,500 psi (259 MPa), rather than 35,000 psi (240 MPa) for the .40 S&W, and the bigger case limit, which permits the utilization of heavier shots and more smokeless powder.