I like it! Why did't I think of that!?! We could expand on that so the diameter can be computed with one set of parameters and the trajectory between 100 and 400 yards can be computed with another set of parameters. Now let's see, we'll just take the secant lay of the Gudermanian of a and....
The reason for this thought is that, for example, you have several cartridges of the same diameter. The names vary like .22, .223, .224, .225, 5.56mm, etc. I think a little creativity could really expand this. Imagine what you can do with just fractions. We've still got a long way to go before we get more confusing than the Continental Europeans, with all the proprietary cartridges with the same names, but different dimensions. But you gotta start somewhere.
Other units of measure have yet to be explored also. For example, angstroms, picoparsecs, and so on.
Ricciardelli, I'm just holding a mirror to some of the absurdities we live with. I think it's because I've been reading about the era when everybody and their pet dog had a wildcat named after them. This is just a logical extension of that sort of nonsense. Of course, I still have my own wildcat, the .45 Questor, which is a 45ACP cartridge shortened by 1/1000" and loaded to velocities and bullet weights that match the 45ACP. It's amazing how many people use this cartridge and don't even know it.