Originally Posted by SouthernBoyVA
...Inertia dictates that a lighter bullet will accelerate more quickly in a shorter barrel than will a heavier bullet which relies on more barrel length to develop its velocity.
Bingo. After all, the majority of shots are going to be within 25 yds. (and a lot less for civilians) and velocity loss does not even enter into the equation at that distance for all intents & purposes.