I'm messing with snap caps. I've never noticed this before because I've never done this before. My kid is sleeping in the next room so I wanted to be really quiet. I loaded a snap cap, pulled the slide back and very slowly guided it forward. The result is that the slide gets stuck and doesn't fully close. However, if I rack the slide the normally or even if I guide it forward gently but not very slow, it doesn't happen. When not loaded, the slide will go all the way forward regardless of whether I rack it normally or guide it very slow.