There are two benefits to a minigun-style barrel.
First off, the barrel is a failure point for a weapon. It gets hot from bullets firing. If you try and shoot too many bullets through it too quickly, it can overheat and fail pretty catastrophically. By rotating barrels, you are only shooting a fraction of the bullets through any barrel, giving them a bit of time to cool off between each bullet, increasing the time before it has to stop firing due to overheating.
In addition, with most guns, you need to load a bullet, fire it, and then unload the casing before it can fire again. With a minigun, you can accomplish these tasks in parallel — you can be loading a bullet in barrel 1 while firing one in barrel 2 and unloading one in barrel 3. This can speed up your effective fire rate quite a bit.
Latest Answers