Ringman,
I have got 3900 fps from my 257 Roberts Ackley improved 75 gr Vmax and the brass could not be used again. That was brass I had to form the shoulders on mad

And I have had loose primer pockets in Norma brass I turned the neck mad

But I have 100 pounds of generic 270 and 7mmRM brass. I am never going to reload that stuff anyway. I will be dead or in a nursing home in 20 years. 7mmRM 140 gr 3400 fps works great. Primers pockets are not loose until 2 gr higher. I don't think Willis's collet die is going to make belted brass pushed that hard fit in other chambers.

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps