Take one you've chambered that way and look at the bullet in it. Can you see little nic's around the bullet? If there are, your probally getting the bullet's into the lands and need to seat the bullet's deeper. If thats not it and you've already run several into it, look at the bolt face. What your looking for is brass rubbing off the back of the case. If you do have that and not land marks on the bullet's you can probally shoot them. If you don't want to try that, pull the bullet's and set your re-size die down more and re-size. Be sure and take the de-prime pin out of the expander plug first. Be careful not to get lube inside that might contaminate the primer. After resizing, run the case into the chamber and make sure it fit's.
Were you trying to partical re-size? If so, for now don't do that. Learn to make good shells befor you try to make great shells. When you put your die in the press, have the ram all the way up with the shell holder in it. Screw the die all the way to the shell holder then drop the ram and screw the die in about a half turn. One of these things should fix the problem. But fix the problem befor you reload many more.
