OK so why is the 5.56 case neck the length it is from the shoulder to the mouth? I know that sounds dumb, but why is it the length it is? The case headspaces on the shoulder. The throat on the 223 wylde chamber (which I have...) has the long commercial throat so the end of the case is not even close to the lands even if it remains the recommended size. What if you trimmed that neck down a little? A tenth of an inch or so. Still enough neck to seat the bullet but a little shorter than spec. A 5.56 wildcat. Interested in the theory of throat length if anyone has such info.