I hunt with a 300 win mag, so I Like velocity, and weight is no problem. Yes, people do stupid things! As you say, only an idiot would cut down a barrel to reduce weight! Larger rounds make sense for the AR platform; the 223 is too small for my tastes (I do like to play with them though). I am biased towards the 6.5 because that size has worked so well for me before.

Idiots should NOT reload! The reason to reload is NOT to see how much powder you can force into a brass case, and how heavy a tip you can ram in on top of it! It is a dance with the firearm and ammunition, to find the sweet spot, that gives you a tight MOA, and hits hard.

Sadly there are a lot of 'reloaders' that will never figure that out!