I'm preparing a 7mm-6.5 PRC project and I'm working on developing some theoretical numbers. Using a Mac means I don't have the luxury of Quickload, which kinda sucks. My reamer was ordered such that I'll be running the 180gr Hybrid in a SA, so sunk down in the case a little lower than I would've liked but remain satisfied with nonetheless. I'm trying to figure expected velocity for different powders, so I got to thinking about how I was going to do that. H20 is the obvious medium used to measure case volume, so is there a list of water-x powder ratios somewhere? For example, the first powder I want to use is RL-26, so this ratio table might say that a x measured volume of water (maybe 1in3 or 1cm3) is equal to x grains of RL-26. Obviously this is volumetric and therefore dependent on several factors, but I'm just looking for a generalized estimate. How cool would it be to have an app where in a guy could select his case dimensions, bullet, OAL, and powder and get a approximations on case capacity/volume, velocity, etc. Is that Quickload? Like I said, I've never used it. Anyway, thoughts on the ratio table would be appreciated. Or, if a better way exist please feel free to share