Never had any ammo problems with any of my ArmaLite rifles, four are older with the 'match' chamber. My ArmaLite AR's with the most rounds through them are 2 M4C's purchased in '98, both with the tighter chamber and chrome lined barrels... each has had over 11k rounds through them... Q3131a, LC, and Wolf, never had any failures whatsoever. All of my ArmaLite's will eat Wolf all day long...
You see numerous complaints of ammo problems but the reality is poor maintenance of the AR is usually the real problem...