Nope; There's no such property for the damage amp; the only signifying action that is made when it is/has run out is the DeActivateSound, which is as default Sound'Botpack.Pickups.AmpOut'.
btw; if you open up unrealed, go to the actor browser then export all scripts, you will get ~15-20 folders (depending on how many packages you have loaded) of the actor scripts.
If you're not into coding/compiling, simply rename them all from *.uc to *.txt, then you can do text searches in windows to find what you want.
Most of what you will want to tweak will be in the defaultproperties section in each file.