OP,
I think Idaho and Robert have given you some extremely useful advice. If only to piggyback on that, I think you really need to take a good look at the path you are considering travelling down here…
Firstly, you say that you practice both judo and wrestling…I believe those should easily see you through the vast majority of “street fights”, if you will. Provided you are a generally peaceful man who avoids fights in public as a general rule, of course…
Which leads to a question (or two). Be honest with yourself when I ask these:
Do you have it in you to kill someone? Have you given that question sufficient thought, all the way through to its logical conclusion? If you have, and the answer is “yes, to defend my own life or that of another” then I commend you!!! And I now advise you to save your money, pinch your pennies, and get a concealed handgun license. Then, MAKE the time to learn how to properly use a handgun in self-defense. Then pray that you will never have to. Because if you have decided that you CAN kill someone, if necessary, then why are you handicapping yourself by carrying a knife?
As Idaho pointed out, killing another person with a knife IS NOT easy. It is no small thing to close with your enemy to touch distance, and then carve up his vital organs until enough of him bleeds out onto the pavement to cause his body to shut down. People don’t just drop like they do in the movies. And frankly, it takes a LOT more commitment than killing someone with a handgun.
Further, a karambit is designed to do nothing but cause damage and kill…if you DID have to use it for its intended purpose, and you got a prosecutor with a bug up his ass, he could easily present it as a specialized weapon that required specialized training to use…and then make it sound like you were basically walking around WANTING to kill somebody.
HOWEVER…let’s assume for the sake of argument that you have given all of this ample consideration.
The answer to your question regarding using a karambit in circumstances where a gun could be used is GENERALLY going to be “yes”. IF you are justified in the use of deadly force in your particular jurisdiction, and under the specific circumstances, then your weapon of choice matters very little. So, the best advice I can give you is KNOW THE LAW in your jurisdiction regarding self defense. Tread carefully, do everything you can to avoid confrontations that lead to deadly force encounters, and realize that just because the law says you CAN do something doesn’t mean you SHOULD do it.
Cos I’d be willing to bet there are lots of guys in prison right now who wish they had spared their attacker’s life. Juries are unpredictable, and don’t always see things the way you do. I’d rather be free than “right”.