If you are recoil shy you are going to hate life with a 300RUM, and you aren't going to want to carry a 12-14# rifle in the mountains. Disregard your "mentor" and his speed freak issues. The 200fps difference between a 300 RUM and a 300 Win Mag or PRC is negligible for any meaningful metric other than possibly extreme distances.
My buddy has a 9.5# 300PRC and it's a bit sporty to shoot even with a suppressor attached.
The advice Idaho Lefty gave is pretty solid. I have a Tikka T3x Roughtech 300WSM that weighs 9# and it's reasonable to carry, and recoil is very manageable. And it shoots well under MOA.
My buddy has a 9.5# 300PRC and it's a bit sporty to shoot even with a suppressor attached.
The advice Idaho Lefty gave is pretty solid. I have a Tikka T3x Roughtech 300WSM that weighs 9# and it's reasonable to carry, and recoil is very manageable. And it shoots well under MOA.