Ok, one more thing I am wondering.
As far as book loads are concerned, I realize that different length barrels - different lots of powder/primers - different types of bullets(even if they are the same weight) - different cases - all come into play when they test their loads and list velocity.
My question is how pressure relates to velocity. Lets say that the book lists one load, and I have matched everything to a T with what they said they used, of course except for the actual gun. But my loads are 200fps slower than theirs. Does pressure equal the velocity for the given bullet? Or is it a factor of the rifle they used that accounts for the lower velocity in mine, and could the same amount of pressure be present in my gun - just not reaching the same velocities?
I should have paid more attention in my physics class, but it seems to me that it would take the same amount of pressure to reach a certain speed if the barrel lengths are the same etc. But at the same time I realize there is probably more at play here. Anyone dove off into the deep end with this kind of contemplation?