My 7mag shot H1000 well but I was up around 70gr. Keep bumping the powder up till you find pressure. Your gun was throated for a 180 which means you can’t go by book/saami specs because you OAL is longer. Go toward 70 and if it doesn’t shoot, then try another powder. Re26 would be great if...
Need to have a smith look at the chamber. If it’s getting stuck it could be an oversized chamber causing the brass to squeeze down too much in the die. Also could be all the marks on the brass from the chamber catching in the die.
Your throat could have been rougher than normal and caused the barrel to Copper up. I had a 300 win that took forever to break in and settle down without excessive Copper fouling. I’d shoot clean, shoot clean a few times then try 3 shot groups before cleaning. Do make sure you’re not jamming in...
I’d never swap from that combo if I was you. I wanted to do the same thing but couldn’t find any 130’s. I ended up getting some 150 maker Trex bullets (allot like Barnes). Getting 2900 in a 20” barrel with excellent accuracy. About to try it on some live targets.