Interestingly enough, I just finished up some training provided by USCPB (Customs and Border Protection) yesterday. You probably don't have to worry too much about being searched crossing northbound. Coming back, however, is a whole different story. Trust me when I say that there is very nearly no such thing as a "random search", no matter what you are told by whom, or what "official policy" you may come across. Most of the people who are searched get to experience that as a result of their answers to interview questions, the appearance of something being "not quite right", or just on a hunch. These officers, (don't call them border patrol, that's a different agency), are highly trained to pick out the smallest inconsistency, and to spot the smallest abnormality. Here's the really fun part: If a CBP officer wants to move up in pay grade in the agency, the best way to do it is to get lots of drug or weapon seizures. They are actually incentivized to bust you. You might get lucky, or you might get very unlucky. If I were you, I'd leave the gun at home. Last I heard, baseball bats are still legal to cross with.