 Gettysburg Trading Post. We buy, sell, and trade. Getting low on ammo? Set your sights on Gettysburg Trading Post. Gettysburg Trading Post carries the area's widest selection of handguns, rifles, and Maryland-compliant firearms. And new ammo is always arriving daily. Where we buy, sell, and trade. Everywhere I go, people want to talk about politics. People in waiting rooms, people in bars, people in Uber. Like, these people are extras in the movie that is my life.