I have found that the most consistant primers have been the WLRM's. Across a chrony, they give the least deviation, and they really tightened up the grouping with the 25 06. I tried the others, and found that the Remingtons were the most inconsistant, and the Federals gave me up to 50 fps deviation I managed to get my velocity deviation down to 10 fps with the Winchesters, in the magnum rifles. I will only load with the Winchester magnum primers, in the standard and magnum cases.