I bought a 300 win in the m77....It would like to have beat me to death...I am 6' 200lbs & I was going to sell it for a 30-06.....I saw the lead sled advertise & recently purchased one. I can tell you as I shot the first round I was very ansy....expecting the kick......I felt NOTHING!!!!!! The lead sled is an awsome tool to have. I shot my rifle better than ever before. Can't imagine life without the Lead Sled....
I say stay with the 308 unless you really need the upgrade.