Yes I know he wanted to know about the 06, but the problems he is having are things that I have experienced in reloading.
I'm fixin to do 3006's .... but my main point is that if you change too many things at once, is not the way. The case length and crimp or no crimp are critical and can deform a casing. Start medium range on powder (also bullet?) and work up to a hotter load , all the time watching for over pressure signs. What I am saying is . This problem is normal for any caliber. Not just that 3006 ....