Wow, you guys are hugely helpful. Its going to take a bit for me to digest all of this info, but I'll come back if I have more questions.
RE: The photography stuff
For this kind of photography, the shutter speed of the camera is largely irrelevant. Most normal cameras only go as fast as 1/8000 of a second, which isn't even close to bullet-stopping territory. Usually, this will be done in a dark setting (IE outside on a private range at night) with strobes. A normal hotshoe strobe will go as fast as about 1/40,000 sec duration on low power, which is good enough for a lot of things but really not up for stopping a full-speed bullet. I really need 1/1,000,000sec durations, but strobes that do that and still have a reasonable amount of power are tough to find. I'm going to need at least f/5.6 to get enough depth-of-field even with a tilt-shift, and would prefer to keep my sensitivity 1600 or (preferably) less. I am going to test this weekend to see how bright the muzzle flash is: I will need at least enough light from the strobes to balance with the muzzle flash. I will be using something like this: as a triggering device.
http://www.universaltimer.com/
I would like to actually capture both the gun and round, with the round just having emerged from the barrel.
Since its a subsonic round, it seems like I might be able to use an audio trigger (it hears bang, and flashes after a pre-programmed delay)... but I may have to find other options like the IR beam if that doesn't work. Again, all of this will be easier if I can slow that round down a ton.
I am not nearly proficient enough with electronics to make much headway with a DIY strobe... But I'm looking at the possibilities of sourcing one from someone who is that proficient.