Personally, I have been using Hornady brass. My reason is cost. I shoot PRS and in a lot of the matches, I shoot I rarely recover all my brass. A lot of times if I do it is caked in mud. If I lose 15-20 pieces of Hornady brass that I got for $0.20 apiece I’m not too upset. If it were Lapua however it starts to get pretty expensive. I may be able to develop a more accurate load with Lapua Brass but honestly, in a PRS match, I don’t see it making a significant difference for me. Getting a stable position and practice is what matters with positional shooting. Being able to print a group that is .25 MOA smaller doesn’t make that big of a difference at my level. Now if I was shooting f class where the .25moa makes a huge difference and I knew I would recover all my brass it would be a different story. I would probably just keep all your brass. Load the Hornady with a 140-grain bullet and load of choice and use the prime to try out some lighter bullets and see what your rifle likes better. I have about 100 pieces of Peterson brass also. I have been using those to load reduced loads with 123-grain bullets for my son. No reason you couldn’t do the same to experiment a little and see what your rifle likes.