It happened to me 2 weeks ago, not bad, and drew a tiny bit of blood. I was spending too much time trying to correct for my wobbling and not paying attention to my position behind the scope, it was set to 8X.
2 things, the SA ar-10 recoil isn't near as bad since I replaced the buffer with a heavier one last week. I also discovered that my wobbling occurs at magnification starting around 3X. I haven't shot rifles w/scopes in many years since I was working too many hours. I realized at 1X -2X I was fine. So it's just me chasing the target at uppers powers, my older age and years away from the scope. I'm sticking with 3X for now and I'll slowly work my way back up 1 power level at a time.