Usually a Semi-Auto, but they can be revolvers that have stuff like compensators, red dot sights, skeletenized hammers and triggers and very light trigger pulls. They are usually pretty heavy to tame recoil even more. They have everything made for the type of gun to make them shoot faster, reload faster, more accurate and to tame recoil. They are very impractical for real world use, but ohhhhhh are they fun at the range. They are used for shooting targets really fast.