Many shooters believe the SRM primers perform better than others in the 6mmBR. So this summer I switched from CCI BR4's to the CCI 450 and Wolf SRM's. I am unable to see any difference. Primers are usually the one component which does not dramatically affect accuracy or other factors, i.e. ES, SD or MV. Slight increases, yes, but large difference, no. Try them over your chrono and make your best judgment.