Disappearing Ammo

I was playing Ghost mode and I had AWM in Bag 1 and AK Silver in Bag 2. I did not want the AWM for GM so I switched to Bag 2, only to find my ammo clip is smaller. It only happens when switching.
Here is a video to show. Sorry for the bad quality and if this has already been mentioned.
http://www.xfire.com/video/311abc/