The velocity stated in the Federal page of Federal Hi-Shock (9BPLE)+P+ 9mm 115 gr. jhp is 1300 fps, why is slower than the Cor Bon (SD09115) 9mm +P 115gr. jhp 1350 fps and much slower than the Double Tap GD 9mm +P 115 gr. jhp at 1415fps?? Shouldn't the higher +p+ pressure drive a same weight bullet faster?