Out near the Rocky Mountains, Ben Meager found a good spot to park his robot vehicle. It was the best place to park in a lot packed with some of the defense industry’s newest tech, but it also happened to sit next to a counter-drone turret he’d been eyeing for more than a year. Meager had made renderings of the turret, an autonomous machine gun drone killer made by Allen Control Systems known as “the Bullfrog.” He thought it could fit on top of …