commander barrel, the hollowbased 45 gr solid aluinum bullet, and and powder taken from 22lr ammo. I'm assuming that .22 powder is faster burning than Bulleye, but such might not prove to be the case. if not, then the next step is powder from .22 blanks Given that the bullet doest have to obtur to the rifling for an inch of travel, pressures should drop a lot, almost instantaneously, as the bullet moves so easily down the bore. I suspect that 2400 fps can be had.from a regular 9mm case. I fully understand that you wusses cant figure out how to do such a thing safely, working up a load half a grain at a time, while chronographing each shot and miking the case at the web, but I can do so.