I've been front squatting for about six months. I don't do any Oly lifting, so I use the cross-arm grip. When I first started, it was painful as hell with just 185, and it was very awkward. IIRC, it took me about two months to get comfortable with it.
You shouldn't feel any pain in your shoulder bone. You're probably not keeping your upper body tight enough. Try to you keep your chest up and keep your upper back and traps really tight--pretty much like the top of a shrug position. That way, your shoulders will be flexed, and the bar will sit on the meaty part of your shoulder muscles instead of on your bones.
You shouldn't feel any pain in your shoulder bone. You're probably not keeping your upper body tight enough. Try to you keep your chest up and keep your upper back and traps really tight--pretty much like the top of a shrug position. That way, your shoulders will be flexed, and the bar will sit on the meaty part of your shoulder muscles instead of on your bones.