Last time I checked, you just keep the ammo when you drop it.
Unless that's your existing code screwing you over for 3 clips.
If you have an AK with 3 spare clips, and swap your AK with someone who only had 1 spare clip (both drop + pick up each others) you would both have the same BPammo as you started with, but whatever gun-ammo was in the other guy's rifle.
Try scanning offsets and that after slaying yourself instead.