I have a new 16" AR15 (BG Defense Type-A) rifle. It ran fine the first two trips to the range and during an intro AR class (~140 rounds total), but last night I had a dozen or so failure-to-feed malfunctions over ~120 rounds during a second class. The gun would fire and start to feed a new round, but the new round would jam up at an angle with little forward movement (i.e. the entire round was visible through the ejection port). I was shooting Winchester White Box .223, which I had not tried before, but I was also using new magazines for the first time (Magpul Gen3). I suspect the problem is with the ammo, and I'll first try firing the brand of ammo that worked previously (GECO DTX; both are 55gr FMJ .223).
What else should I look for? If the problem is just with one brand of ammo, should I work on making the gun reliable with that ammo, or just use other brands? If the problem persists with other brands, what's the next step? The gun was clean and lubed, and I cleaned it today and didn't see anything unusual (except some carbon buildup on the "tail" of the bolt beyond the gas rings, which I've heard should not be a problem). Thanks in advance!
What else should I look for? If the problem is just with one brand of ammo, should I work on making the gun reliable with that ammo, or just use other brands? If the problem persists with other brands, what's the next step? The gun was clean and lubed, and I cleaned it today and didn't see anything unusual (except some carbon buildup on the "tail" of the bolt beyond the gas rings, which I've heard should not be a problem). Thanks in advance!