Originally Posted by Swampy
Smith and Wesson M&P 15 is nice rifle, or if your looking towards more of a deer hunting caliber bump up to a AR-10 (.308 or 7.62 NATO).
Or if you don't like AR look but want the reliablity of combat rifle. Springfield M-1A (M-14) is nothing but bad @zz.
There shouldn't be a issue firing 5.56 or .223 stamped ammo. There is no difference between the two. The only thing you might have a issue with firing stamped 5.56 if it was belted or de-linked machine gun ammo.
If you research the issue, there is a difference betwen 5.56 and .223. I think and, please don't quote me as I am going strickly on memory, that the 5.56 is loaded to much higher pressures and there is a slight chamber/throat difference that may lead to problems when firing 5.56 in a .223 labeled gun.
I do not have references to such articles, but have read several.
Now I have fired a lot of 5.56 through my Rem 700 varmit special that is labeled .223 and had no problems. I acutally purchased the rifle back in 1971 when I was in the USAF so I could shoot military ammo. I did this blissfuly for a lot of years before reading of this warning.
You will probably not have any problems doing this, but the warnings are out there and you are on your own when using ammo that is not proper or standard for the chambering.