Yup, your both correct but I still use a slightly heavier bolt than needed for two reasons.
One, its a whole lot easier on your bow
Two, the heavier the bolt, the longer it stays on the string, which causes it to absorb more energy from the bow which gives the bolt more energy, which allows for more penetration through bones, which means less deflection off of bones, which means more deer and less tracking. All this is theory which means I may not know what I am talking about which means
The Squirrel is gonna bash me, which means I said which means too much!
Some stupidity aside as long as you stay with a 22 or 21 sized arrow/bolt yu ok. I would think if it gets too fat the bolt will start getting pushed unevenly. Still I would rather shoot the heaviest that my bow likes which is some where around 450 grains. Heavier means quiet as well.
Did I misunderstand what you said Reb?