Pull buffer and recoil spring.  Take a file to the end of the recoil spring winds and knock off any burs that may be scrapping down the inside of the tube.  Use said file again, and flush out the bumper roll pin to the sides of the buffer.

Now lube the inside of the receiver extension, the recoil spring, and the buffer with a light coat of CLP and reinstall the parts.

Next with the mag out (read rifle unloaded), and the upper's bearing surfaces also lubed with CLP, pull back on the charging handle, and slowly ride it forward.  The B/C should not hang up on anything on the way forward (not worried if the bolt fails to lock/cam over).  If the carrier hangs up on the way forward, do it again, but this time hold the trigger pulled back as you walk the charging handle forward.
Note: if the carrier does bind, then there is a good chance that the hammer is catching the firing pin collar on the forward stroke.

Lastly, pull the mags apart and clean and lube then with CLP.  Also, when you have just the mag bodies in hand during cleaning, run your fingernail down the bottom of the feed lips (where they contact the rounds). If the lips are bur'd/rough, use a stone and polish them out.

Make sure you have a rifle recoil spring and not a carbine recoil spring.


Take a small diamond dust file and break the sharp edges off the reciever extension lugs that make up the ends of the feed ramps.

Carbine recoil spring will be around 10.5" and a standard A-2 coil spring will be about 11.75".