A while ago I started a thread on cheek slap. Thanks for all of those who responded. One thing that was never mentioned is how you hold your jaw when shooting. I've noticed when I shoot trap or skeet I mount the gun with a slack jaw and I'm wondering if in the recoil my jaw moves contributing to cheek slap?
I am a stress clencher and when hunting I mount the gun with clenched jaw and never get cheek slap.
I have yet to shoot a round of trap and keep my jaws tight together to see if that makes a difference.
This happened to me shooting an O/U. I had to find a really good gun fitter to look at how I mount the gun, all the dimensions, and such. We ended up spending 5 hours adjusting it to my body, face, cheek, and shoulder. In between adjustments, we went to the pattern board to make sure the shotgun was shooting where I was looking. You would be surprised how often this is not the case. You should be able to close your eyes, mount the gun into the zygomatic arch, and that's your perfect mount. Open your eyes. Are they straight down the rib? Doubt it. That's what a gun fitter does. You can mount the gun with your eyes closed, and he will make it line up to you each time. Then you can easily shoot low gun.
Long story short, if the gun doesn't fit you, it will beat you up. You're probably just tilting your head too much to the right, so your right eye can see down the barrel.
Dale Tate in Camanche Hills does a great job.
http://daletategunmaker.com 
