Not much of a choice here, one is a known piece of junk that was canned because it just didn't work and the other is a Kahr.
If you can afford it, the Kahr will most likely give you less problems. If you can't afford it, find something else. The Kel-Tec P40 is a bad gamble for a gun that is going to be used for self defense.
Don't forget about a .38 snubbie! I know they have been around for so long that people seem to think they are past there prime but no semi-auto pocket pistol made today will be as reliable as a good snubbie. For a gun that is only going to serve one purpose, the snubbie is the best choice. Just my 2 cents, take it for what it is worth.
If you can afford it, the Kahr will most likely give you less problems. If you can't afford it, find something else. The Kel-Tec P40 is a bad gamble for a gun that is going to be used for self defense. Don't forget about a .38 snubbie! I know they have been around for so long that people seem to think they are past there prime but no semi-auto pocket pistol made today will be as reliable as a good snubbie. For a gun that is only going to serve one purpose, the snubbie is the best choice. Just my 2 cents, take it for what it is worth.