No , the 6CM is off .243 Winchester Brass. My fps is 3153 with 115 DTAC and 48.7 grains of H-1000 and 3225 with 49 grains of H-1000. this is out of a 27 inch Kreiger. 1/4 moa rifle. The fella that designed this cartridge shoots 49.3 at 3275 with a 115 Berger.