Both tools are designed to help you make your own flavorful meat. The main difference is in how they work. A jerky gun has an attached plunger that pushes out ground meats with spices through its nozzle while injecting it into large cuts of meat (like beef, pork, or venison). A marinade injector works like a syringe needle piercing small holes in the meat so that juices can be infused into them from the inside out. They usually come with multiple tips for different flavors. Most experts agree that using both devices together creates some amazing flavor profiles!