Re: case question
BlackEagle - the answer to that is one and the same. The reason that one brass case (if case lengths were exactly the same) would be heavier than another would be because of more brass = less available volume for both the powder charge and the resulting increased pressure from that charge.
Most of us casual reloaders measure our charges - sometimes each and every charge, we often weigh our bullets, insist on the same lots of powder and primers, and trim our cases to the exact same lengths to insure as much consistencey as possible, and get what each of us considers very accurate ammunition.
Bench Rest shooters are a different breed of cat. They are EXTREME in checking and weighing EVERYTHING and ensuring that exactly everything is the same. This includes the cases. Again, as a casual shooter, I like to make sure that my cases are the same maker and, if I can, the same lot of production. A true bench rest shooter would hold their nose and walk away from my ammo.