The Mauser .280 and M70 300WSM went to the range just yesterday as a matter of fact... They both weigh in at just under 8.5 lbs fully loaded on the bench.

33 rounds from the WSM, (handloaded 150 and 165 grainers) no problem effects.
6 rounds from the .280, (150 grain Rem PSP) slightly bruised shoulder.

I admit that the Mauser military stock sucks for shooting off the bench, and I am sort of a lean, bony kind of guy, but...

At a MINIMUM, I keep a slip on pad (forgot it yesterday) for practice sessions! 1 shot hunting will not hurt you, but the range sessions will, and the flinch you get from being slapped around at the range WILL follow you into the field!

The .280 is a pure joy to shoot. The .338-06 wears a Pac. dec. pad. I think a bit of pain would be involeved if it wore a steel butt plate?
CDH, try a PAST recoil pad off the bench, I use one when shooting alot of rounds form the bench or kickers, usually .338-06 & up. Everyone feels recoil diff. Maybe I just shoot that .338-06 too much.

The Past Recoil pad is what I'm fiquring. It really works well.