Yes I use a spinjag and try to load with the same pressure.....I can't tell much difference in how tight the hph12 with the sst and the short black with the xtp. Like I said earlier in a post, several buddies of mine shoot the 250 sst with the hph12 and I can tell a big difference in how tight theirs loads. They all shoot good groups and on a consistant basis. I feel like my bore is much more loose than theirs. I can shoot decent groups but not consistantly. My best groups at the range are my first shots with a clean barrel. I'm hoping a load that will fit a little tighter will help.