The only .308 I have owned was an older Remington 600 (I believe I cannot really remember the specifics). The rifle was very light, ~6 lbs., and beat the snot out of me. I am sure that the very thin hard plastic butt pad did not help much. I fired all of seven rounds through it and was black and blue up and down my right shoulder and chest. I admit to being nervous about trying another .308. I would hope that the m14, G3, and HK91 would be much less painful being semi-auto and quite a bit heavier. Has anyone seen or tried the Kel-tec RFB?