Originally Posted by Phantom465
From the info I have Googled, 5.56 and .223 are virtually the same size, but 5.56 usually has higher pressure. Is that correct?
With that in mind, what parts really matter when it comes to higher presser. Certainly the barrel needs to be rated for higher pressure. What are parts should I be concerned about?
Rifle made for 556 will shoot 223 as well but not the other way around. 223 rifle will not shoot 556. There is a difference in the dimensions. You need to look at more than the caliber