One of the problems with the AC-130U 25mm gun is the inertia of the ammunition. The gun spins so fast that about 6 rounds continue to go through when the trigger is released. Because when you move it, it's hard to stop all those bullets. The feeding system was actually reversed to save these unfired shells. Getting this feature working is a huge pain during development.
It's great to be able to see the whole process of loading those really big rounds of bullets for each shot and also to see the size of the bullets for the automatic gun. A really long magazine with a lot of bullets.