Gah. Another one for me.
What is this, the ruin Kara's week thread? 
EDIT : In the future try running a debug build before submitting a bug. The second I ran the mission it was pretty obvious that not setting a capacity for the bank is the issue here.
No no no. That is NOT the issue. I've run FIVEHUNDERED debugs on my own mod. I've got all tables set up perfectly. The SEXP DOES NOT WORK. It will reset the damn counter to zero.
The test mission was very quickly put together just to show that the sexp doesn't work ingame. For some reason I managed to forget to add $PBank Capacity: (100, 100) to the uly-shp.tbm. Add this yourself and see that the sexp is going to reset the ammo counter to zero.
The Sexp IS broken. Even Without the $PBank Capacity: line the capacity is defaulted to 1. Hence why there is ammo in the weapon at the start of the mission. Please do not draw the wrong conclusions and Pretty please fix the sexp.
edit: oops, I misspelled hence again, better fix it before QD comments on it again
