I have an MAK-90 in .223 that has begun starting to have failures to extract.  I'm using Wolf 55 grain FMJ ammunition.  Oddly, it almost seems to have more problems during slow fire than when just dumping a mag out as quick as you can.  The cartridge is stuck about 1/4 to 1/2 inch from the breech and the only way to remove it is to drop a cleaning rod down the bore and hammer at the brass while pushing the bolt back.  Any ideas?  Thanks for your help.

It's hard to say how many rounds I've put through it.  One to two thousand, anyway.  I haven't tried it with other types of ammo, but the next time I go out I'll bring along some American Eagle I've got and try that.  The Wolf ammo had problems despite coming from two different batches.  Of the two jammed cases I have, one has a pierced primer and other looks fine.  Thanks again for your help.

RotDorn,
 Thanks for your help.  It's odd that this never happened before, but I'll try it with the American Eagle stuff.  I'll definately keep you posted, but I'm not sure when I'm going out again, time and drought issues being what they are.  Thanks again.