Johnny,
2 things in your posts cause me some concern. First, having loose primers after even 4-5 firings is still an indication that your loads are too hot. Over pressure can be cumulative so because your rifle didn't come apart with a particular load you could still be doing damage that will cause it to come apart in the future. Second, the problem with light primer strikes could be due to bumping the shoulder back too far causing a headspace issue.
Not flaming you or anything, just want to make sure you are being safe.
