[wyobohunter]

Others will likely chime in with a solid answer. I don't have one but am interested. A few observations and peanut gallery type comments.

1-I believe it is illegal to make your own BP so I wouldn't advertise the fact, though if you are only talking about what could be done in a very bad situation I don't see the harm in discussing it as an option.

2- 45 Colt was a BP cartridge as you probably mentioned, I think that'd be a good one. The old BP loads were not nearly as powerful as the modern smokeless "Ruger only" type loads. I don't think over penetration would be as much of an issue as one might think if you loaded to "cowboy" specs.

3- I know for sure that BP pressure is generally lower than smokeless, that's why smokeless velocities are so much higher. I believe BP does not burn slower... But faster, I also believe this is part of why pressures and velocities are lower. Someone else can probably explain this to us and correct my misgivings if I have them.

Another option is to stock up on a cheap but serviceable shotgun powder. For example I've worked up a nice load for 45 Colt using a Remington 2 1/2 primer, 7.0 gr of Alliant Red Dot and a 200 gr HSM cast at 839 fps. Start load with this powder/bullet/primer is 6.6 gr and 7.3 gr is max. This is out of a 4 5/8" barrel Ruger Blackhawk. Red Dot and other shotgun powders are a pretty cost effective way to stock up on something that works for lots of handgun loads. A pound of Red Dot makes 1,000 of my loads. A pound of that only goes for about $18, and is even cheaper when bought in bulk.

If you are ok with a two shooter, the Bond Arms 45 Colt may be worth a look. I'd like to get one myself. One of them even comes with a nice crossdraw type driving/concealment holster. The shorter barrel would reduce velocity even more but I'd bet my next paycheck it'd be a solid one shot man stopper.

Very interesting question; I look forward to more folks adding to the discussion.