I have a 308 and 270 which I did stock stiffening routines on. My 270 shoots a bit better than my 308--not sure why, but my observation is that these are lightweight flexible setups for calibers that deliver significant recoil--the whole challenge for me has been keeping the weapon still during shooting. I've started taking Zen-master Yoga classes so I can figure out how to hold the rifle without actually touching it. : )
50 yds is a tad close for comparison--what do you get out to 100?
Bookmarks