I went out shooting with a couple friends on Saturday. I brought my Glock 19, Springer GI, Savage MKII and my Spike's/Stag/RRA AR. I only brought enough ammo to fill about 5 mags for the AR, some of it was factory Speer .223, some was .223 that I had loaded myself while I was working for the gunsmith and bought a couple boxes, and one box was Lake City 5.56 (my RRA upper is rated for 5.56), all of it was 55gr. I emptied a mag, then passed it to one of my friends to shoot. He shot maybe half a mag (not wanting to use up much of my ammo), put it on safety and handed it back to me. My natural reaction was to pull the charging handle and check the chamber. The round was in there very tight, almost stuck. I shoved it back in with the forward assist and emptied the rest of the mag with no problems. That was with the Speer .223. A little later on, after letting the AR cool for a while, my other friend loaded a mag with Lake City 5.56, shot half the mag and handed it to me. Again, I checked the chamber and the round again appeared to be stuck, but then got past the tight spot and ejected. I chambered another round and shot the rest of the mag with no problems. Has this happened to anyone else?