Printed a magwell for my AR-15. Would of printed the vertical grip and all that too, but already had these accessories laying around.
I'm guessing there isn't much I can do with my Glock? I looked into printing a Dime Job for it, but it defeats the trigger safety, so I didn't really care for that idea.
I printed a brass catcher for my AR. Be sure to consult local laws tho, since they are surprisingly illegal in some places.