[rg1]

For one tip would be to lube every case the same and lube the inside of the necks equally too. If you don't lube the neck id you can pull the shoulder forward pulling the expander back thru the neck. It will make a difference with shoulder set-back especially if you are sizing without firm contact with the die and shellholder. Some brass just has more spring back than other cases too. I'd guess that the chamber of the bolt action is minimal and the other is on the long side of specs. Possibly a little firmer contact with the shellholder and die and hard equal pressure on the press arm at the end of each stroke will help. My Co-Ax doesn't seem to have any problems with press looseness but it does need positive firm pressure on the handle at the end of the stroke for sizing and bullet seating for things to be consistent.