I received a 24/47 from AIM. After cleaning it and getting my order of brass, dies and special ordering a cast bullet sizer - I have found the bolt extremely difficult to close and open on a case. I have to really force it closed and open. The brass gets a little boogered up in the chamber. The gun looks like it has never been fired. I cut off the shoulder area of a case and it is still difficult to close the bolt so it shouldn't be too little headspace. This is my first mauser, any ideas??? I'm thinking the lugs may be rough or have burrs.....