the´re just odd shaped bullets, but they need adjustment on the power used to fire them do to different weights and mechanisms, He needs the gun able to fire anything of that sort, so he needs to modify it to his specifications. like a the batbelt but for shooting all sorts of things, glue bullets, oil spraying bullet, nets, etc.

Edit: ( NP sable, we all have shitty days, just get back as soon as you can )