I've always assumed that velocity for a given weight of bullet is a proxy for pressure. I also have always thought that when we match bullet hardness with different velocities that this was really relating the pressure to BHN relationship in a easy to apply way. Then I remembered that in the early days of BP cartridges velocities were kept to under 1,200 fps (ignoring paper patching) and the larger and heavier bullets were used to design cartridges with more power while keeping velocity down.
Lately, I got this idea that I could avoid gas checking my 357 cartridges by just using a less powerful loading; simple so far. Then I got to thinking that it would be a good idea to develop a less powerful cartridge that duplicates the trajectory of my full power 357 loads. This is for my Marlin carbine. So, if my regular full-power load has a 158-grain bullet moving at 1,400 fps, I'd make cartridge with a 125 grain bullet that also travels at 1,400 fps, and then tweak the load until I match the trajectory.
Then I started thinking about it and am wondering if it's true that velocity is just a proxy for pressure. Because if it is, then I don't think they would have designed BP cartridges with the 1,200 fps limit that they did in the old days.
Can anyone clue me in on this?
Thanks,
--Jeff