weapons with intresting physics

im intrested in creating a weapon that shoots balls like a paintball from a container id like so that when a “ball” is picked up it adds it to the container and it can be seen inside the weepon have there be a system to that until the ball is fired the next ball wont load in and the next ball loads in is touching the load hole it removes it (so works like a gumball michine) id pay for this weappon to be made and programed please give me a quote thanks. or any information to creating it myself im not lazy also first time posting i hope i posted this in the right spot.