Slake: Are you mounting your rifle out on your arm? If so, you have to lift that arm up so that your elbow is parallel with your shoulders. Then, when you mount the gun push it out away from you , and bring it to your face, rather than mounting it to your arm, and then lowering your face to it.
I found that most stocks are too short for me to shoot well if they are mounted on my arm. I now shoot shotgun style buttplates, and mount the guns in the pocket of my shoulder, as I would a shotgun. That allows me to stand with my head up and straight, no cramping neck muscles by leaning over, and I can bring the stock to the side of my face. If I mount the gun to my shoulder, first, and then lower my head, the stock will beat on my cheek everytime.
If our gun has a typical hawken style half moon buttplate, you may have to change it, as I eventually decided to do. However, I shot one of those for years, and learned to raise that elbow up and out so that the butt was higher, and the stock would lay alongside my cheek, and not below it.
The other thing you should consider is shooting lighter loads. I don't think your manhood will suffer if you finally realize that all the power you need on a target range is enough to push the ball through the paper. I have a friend who weighs in excess of 300 lbs. and stand about 6'3" tall, who used to shoot heavy loads all the time, until his shoulders began to act up. He had built a .32 rifle for one of his daughters, but after she left for college, it just sat on his gunrack. One month, he decided his shoulder was too sore to shoot his usually cannon, so he took that gun to the range, and shot the match with it. Won, too. We kidded him a bit about using a kids gun, and he just smiled, and said he probably was going to use that kids gun again next month, so just get used to it! He had us pegged. We were all a little jealous, both because we didn't have one of those rifles, and because he had found a nice solution to getting a sore shoulder every month proving how manly he was at the club shoots.