I have the same rifle you do and love it, good choice. I reload the Hornady 55 FMJ's also and seat them to 2.230 with a light crimp, not sure why you need to load them that long. Also with H335 I use a mag primer and prime off press and have never had a problem. You didn't mention what dies you use but I would invest in a Wilson case gauge to set your resizing die. Another good powder to try if you can find it is TAC. I get real good groups with TAC and a 55grn FBHP bulk bullet seated to 2,250. The only thing I changed in my rifle is the trigger, dropped in a Timney and made a world of difference over the mil-spec trigger.