So today I had a humiliating experience at the range, when I really put some rounds through my Mosin Nagant. At 100, even 50 yards, I grouped horribly, if you could even call them groups. Shots were spread out all over the paper. I wanted to sight it in, but I couldn't because I couldn't even make any decent groups. Now, I know I can shoot decently. I consistently grouped my .22 within 2" at 50 yards, and managed to make 4" groups shooting slugs out of my shotgun w/bead sight. Not amazing, but good enough. My mosin isn't at fault, it has a good bore and strong rifling (my BIL who is a USMC armorer checked it). I was shooting Prvi Partizan ammo. Also, I have a good grasp on breathing, sight picture, and trigger squeeze. Not to mention I was mostly shooting from a bench. I left the range with a bruised shoulder and ego What am I doing wrong? I know I need to practice, but any tips, is there anything different when shooting high powered rifles as opposed to rimfires? I really want to become proficient with this rifle.