When it comes to welding, too much of a good thing can often add up to unnecessary costs, potential downtime and lost productivity — especially if you have too large of a MIG gun for your application. Unfortunately, many people believe a common misconception: that you need a MIG gun rated to the highest amperage you expect to weld (e.g., a 400-amp gun for a 400-amp application). That is simply not true. In fact, a MIG gun that provides a higher amperage capacity than you need typically weighs more and may be less flexible, making it less comfortable to manuever around weld joints. Higher amperage MIG guns also cost more.