Make sure you don't have any handguns hidden away in your toolbox. I know a lot of guys from Texas who keep one in the truck, but, haven't thought about or looked at it in a long time. Ditto specific handgun ammunition, they will tear the vehicle apart if they find a loose round of .357 or .45 that got under your seat somehow, looking for a handgun. That goes for spent ammunition in specific handgun calibers also. You will be hating life if that happens to you.
Mr. Wood and Cman have given you good advice. Document your guns as yours with US Customs long before you get there.

Have a safe trip.


Best,
Ted