I have always used CCI mag primers, but, a buddy of mine told me to try Winchesters...he likes them. The CCI have always worked well for me!..........One thing for sure, I have noticed BIG differences in uniformity by using Federal Benchrest Primers in rifle loads. I have a number of cartons of CCI and the Federals, and will probably just continue with them, but the point is well made that something as simple as a change in primer can alter the ballistic uniformity of a load.