I have both and like both the.300 and 7mmRM.. My late wife took over the 7 for her rifle the last 10 years of her life.. We mostly loaded it with a heavy load of Re22 and a 140 BTBT.
It killed everything from rockchucks to moose.. Great load.. But it did shoot faster that 3200.. Maybe due to the altitude here.. I like both, simply for variety.. Shooting one caliber or rifle all the time gets plenty boring for me..
