5.56 in .223 rem Barrel?

[luis11]

I know .223 Remington and 5.56 mm NATO are the best in business. Most of the Military cartridges comprise of the thicker walls. The 5.56 NATO is a perfect tool for war, whereas the as a civilian I prefer the .223 Remington. My point is what happens if I try 5.56 NATO in .223 Remington barrel…