It doesn't. If you want to reload, you need to pull it out, clean it, dry it, take it apart, and replace the casing with a fresh round. Then you lube it up and stick it back in. Though, unless that thing is only chambered for .22 LR (5.6Ă15mmR), you'll probably need to see a proctologist to get it out because of the recoil.
I think the more important question is...where is the trigger and how do you prevent accidental firing? I don't want to give away my secret just because I got a little nervous...