I used new brass.

I make .240 Wby cases out of 25-06 brass. With that one, you definitely need new brass. Fired brass is much harder. It takes a lot of effort to swage a belted round from a non belted case, even with new, softer brass. Fired brass makes it almost a no-go...

Sizing 7RM to .257 Wby is a lot easier than forming .240 Wby brass.

DF