Originally Posted by WoodenPlank
OP: The chamber needs to be a 5.56 chamber, or .223 Wlyde (A match chamber specifically designed to handle 5.56 ammo). If you are specifically looking at AR-15s, it has been a LONG time since I saw one that did not have one of those two chambers cut into the barrel.
Also, it's the marking on the BARREL that matter, not what's on the lower.
Thanks - I am building an AR from the ground up. Are there any other parts that I should be concerned about? What about the bolt / bolt carrier or upper receiver?