I'm taking a look at my MAG one to see if I can find a way to mount an LED inside the part that attaches the mag to the magwell (rather than the box itself). I feel if I'm just shining light on the ones in the box then they're probably going to have a good amount of time to lose that extra florescence given to them before I manage to fire them.
Also it means I won't have a string of glowing green beads hanging from the side of my gun during night games, but getting the battery in there may be a fair bit of work. Maybe a couple of AAAs.
Bit of a bump but I got up far too early this morning and did this - had to wait until not to give it a proper test. The results are good but the finish isn't. It lights up BBs very well:
It shines on maybe the 3rd or 4th BB from the hop chamber, so they stay pretty well lit.