When I go to load my weapon I have a full mag. I pull back on the bolt n release to load one in the chamber and damn near every time it wont close all the way. Resulting in the sks to read a round in the chamber so the bolt wont release n the rifle will not fire because a malfunction with the bolt. Everytime I must feild strip my sks and apply a lot of pressure to release the bolt. Sooo how can I fix this