I was sighting in a .270 for a friend of mine... with a scope. I don't normally shoot scopes, I have only 2 rifles that have them, and one of those is a .22... and I usually shoot peeps, where I get right up on them. You can see where I'm going... thankfully, my shooting glasses took the brunt of the bite, and I now have a little more respect for the recoil of a .270.
Just so you all know... it doesn't have to be a scope. I was up in WY at a long-range shoot, mostly BP and single-shot rifles. A friend of mine let me shoot his .45-90 Sharps full of black powder... with a tang sight. As I mentioned previously... I shoot peeps like I was instructed by my Army DI... I get my eye right up there. The good news is I hit my target at 900yds, but I never saw it because I was seeing stars by that time... the recoil rammed the tang sight base into my chops, I literally thought I knocked my front teeth out. As it turned out, I have a nice dueling scar on my upper lip, teeth intact... and a little more respect for those big BP rifles...