I purchased a Colt AR-15 the day Obama made his first post-Sandyhook speech. I only paid a $300 mark-up - instead of the 100% mark-up that is now common. I have only shot a couple hundred rounds so far (at most). I am getting a double-feed nearly every magazine! Is it the magazine? Does the rifle just need to be broken in? Is it the ammo? I have a few other magazines available both new and used, and I'll be running those in turn ASAP.