I've shot a lot of Federal primed .223's out of several AR's with no issues. It's only recently that I've had a couple instances of auto-fire. Not a comfortable thing. I simply won't be priming with Federal's anymore, except for a brick I bought about a year ago that are specifically for AR's. I think those will be OK. If I were you, I'd use something other than what you used when the auto-fire happened. CCI #41's are probably what I'll use after the Fed AR primers are gone, but I'm also going to test a hundred before I load the rest of those.
