Question for Wildcat owners

Do slugs fall out because they're not pellet-shaped?

Just the shorter ones like 22.5 VKs and the 28g boat tails in my 22cal. You can see light all the way around (except where the o-ring is) all slugs in the mag. There has to be a way to replace the o-ring? It's at least a two-piece mag so how do you press the center out and replace the o-ring? I'm willing to try when I get some time.