Originally Posted by jrl78
@ EW...I almost s##t my pants when you said that. I have a Bush master ar15 stamped 5.56/.223 on the receiver and that is why I figured it would shoot both types. I got it out to check and thankfully it is chambered for both 556/223. Why the hell would they stamp it on the receiver if it wouldn't shoot both rounds?
Cause you can slap whatever you want on the lower, .22 if you so wish. Many of them come with the "multi" stamp to be built as whatever you want. I'd imagine that a factory assembled rifle would be built to accept both. However if it was a used rifle, I'd take more care to inspect it.