I went to the range with a buddy last week and fired some rounds through his old Ruger MarkII bull barrel .308 and was really surprised by the recoil. It wasn't unmanageable but it was still pretty bad. I've shot lighter 7mags and 30-06's with less thump, and I had bruising on my should the next day in the shape of the recoil pad from firing 6 or 7 rounds. .308 and 30-06 are two rounds that I just never know what the recoil is going to be. One gun shoots like a dream in either caliber and the next kicks like a mule, and the only way I can tell which a gun is going to be is to shoot it (especially in the 06). So my question is what factors affect recoil besides bullet weight or load? In the case of my buddies Ruger, I really didn't expect much recoil because its such a heavy gun but I was wrong. I know that a longer barrel adds velocity to a bullet and thus more pressure so would that also add more felt recoil? In the past I just assumed a longer barrel would also add extra weight to the gun and cancel out the felt recoil but I'm not so sure now. I'm also wondering if the rate of twist would affect recoil? The difference in felt recoil between guns is something that has always puzzled me so any thoughts will be appreciated.