Need a bit more information. Is it not extracting, are you using reloads or factory ammo?
Let me give you an ideal. If using factory, then check to see if there is carbon build up under the extractor. It its clean it may be a week spring. Brownells sells heavy extractor spring kits that are really good.
Now if you are using reloads, we may have another problem. Autos stretch the case from shoulder to base more so then bolt guns. Do to the bolt starting to pull the case out while there is still pressure built up in the case.
What often happens, cases dont get resized to factory specs. Midway sells the Wilson Case length gage that measures the case from the shoulder to base or the head space. What you do, is just slide the case in the gage and if its not flush with the base of the gage, then its not propertly sized. This causes failure to extract. Failure to feed, and in extreme cases slamfires. (rear in ARs but happens more often in M1 and M1As.
But without more information its hard to tell in your case.