Assuming that the firearm is:
- reliable
- something I've trained with and can get my hits
I'm thinking .22LR is my cut off point, but If both of those criteria are met, I'm open to consider other options. My primary concerns are that the bullet will get where I want it too. After that, then I'll look at how effective the round is going to be when it gets there, and what some of the other factors are. .22LR may not be as powerful as I would like, but if its the only way I can carry a gun small enough, then I'll take it.