Berry's FAQ says to use low-to-mid range jacketed data with their bullets. You're pushing your bullets with 4.5gr of Bullseye and my reloading manual puts the max load at 4.8 grains. If I had to guess, you're loading too hot.
I loaded mine with the minimum load in the manual, not only because I was using plated bullets but also because I wanted a light plinking load (and these are my first reloads and I'm kind of worried about blowing myself up). If I make it to the range tomorrow I'll come back and give a range report.