Ive been looking into this lately as I messed up and got my 10yr old a .300 savage for his first hunting rifle. I compared the cartridge to my 7MM mag and figured it couldnt kick half as much. Well I was wrong. According the recoil formula I found on line it kicked about 75% of my 7mm. Both shooting 150grain bullets. Too much for my boy. I was able to swap the rifle for a .243 The recoil formula showed about 8lbs with a 100grain bullet and just under 5 lbs with 55 grains. The muzzle energy was close for both bullet weights. Ill see if its true, we are going to try both weights this week end. But according to the numbers the bullet weight has the most effect on recoil.