I couldn't wait. I had to get out with the 320 REALs and good old BP.
Tried 80 and 90 gr of FFg with moderate success. Then I dug out the flask of FFFg. I figured I was shooting the 275 Maxihunters with 100 gr of FFFg so I'll try that. Without adjusting the sights, the POI was 4" higher at 50 yds and much tighter. A little sight adjustment then proceed to shoot a 6" group at 100 yds all arond the bull with a couple in it. I'll take that for now. My shoulder feels like it was in a vise for a week. Between yesterday and today I must have fired close to 100 shots off. That brass butt plate starts to smart after a while when the only padding is a t-shirt. I figured I better quit before I start pulling shots.
But I had to try one off hand shot at the 50 yd target before I packed up and drilled it 12:00 top of the 3" bull.

When you recover, try reducing the charge to 90 gr. I think it'll tighen up even more.

Yeah, it'll do that.Find yourself a piece of carpet about 3/8" thick and cut out a 3" x 8" section and put it in your range box. It's great between your shoulder and the rifle butt when you're bench shooting with heavy loads and light clothing.