Yawn...Just another night at work.
For the record the only time I used tracer rounds was for training or a firepower demo and only in the 40MM. We used to use 105MM Willy Pete rounds for training which were developed as a marking and fire starting round.. I had one rupture shortly out of the tube on a day training line, now THAT was a tracer.
If you want some real gunship action check out the video below, rocking the 25MM on the AC-130U starts at 00:45. The video title is misleading, actually a combination of several types of gunships shooting. If you check out 04:15 you will see the MK-44 30MM Chain Gun that is on the AC-130W and AC-130J.
The new AC-130J actually has a 30MM, a 105MM, AGM-176 Griffin Missiles, GBU-39 SDB, AGM-114 Hellfire, and at some point in the future a variant of the HEL.