Gun under your seat What is the charges?

Depends on where you live. In Missouri, it's perfectly legal to have a loaded, concealed firearm in my vehicle without a permit. However, if I cross over to Kansas, that's a felony, and I'd likely have all of my guns taken away if I got caught.

In short, it's losing all your guns (and you won't be able to purchase/possess a gun ever again), jail time, and a monetary fine. Just don't do it if it's not legal. You don't want to mess with the ATF/FBI.