SpudFiles

I have been working on a cheap marshmallow shooter for sometime now and I finally decided on one.
Here is the prototype. A very simple toy to make costing about as much as a bag of marshmallows.
It is not just limited to marshmallows, in fact my favourite ammo would have to be balls of paper. It can also fire standard size marbles.
Regarding performance, its more powerful than you'd think.
Regarding accuracy, its amazingly accurate. I can hit a roll of tape from 6 metres away.
The tube underneath can hold a torch or laser sight
Next I will add a clip and simple breech loader.

Does anyone know how to make ammo that is soft and will leave a mark when it hits, similar to a paintball. I was thinking bits of fruit hitting a white T-shirt.

a sponge diped in paint on a certain piece of ammo like a paper cone

Sponges do not really have the best flight charachteristics, plus storage and loading between shots might be a bit messy an the player might end up marking themselves.
But I will test it out anyway.
Thanks Amadeus.

I have upgraded this shooter, the new model now has a flexible tube as a mouthpiece. This caused a problem with loading so I fitted a simple breech loading set-up.

Also I would like to thank ProfessorAmadeus for his suggestion, even though I did change a couple of things. Rather than a sponge I used a finer foam, I gave it a couple of wraps with white PVC tape so that it would slide smoothly and give it some weight and rather than paint I use water with food colouring and a bit of sugar.

You should make a mouth piece from a 'T' so it will seal your mouth to your barrel and more air will push the projectile when you blow rather then escape.

I havent had any problems with that, in fact the only place where the air escapes from, other than the barrel end, is the front part of the breech slide.
There is no real way to remedy this as far as I can see except to use a finer file when im filing down the inside of the PVC coupler that I use as the slide.

okay that thing turned out really cool. i love the bolt and the clip like thing for the ammo. i didnt think of using food coloring and paint would gum up your barrel. The ammo that you made most likely improved its flight characteristics and is much more accurate than a sponge alone. All in all it turned out great!

Actually I changed the ammo again. I chopped off the front piece of foam, leaving just the back piece of foam sticking out of the roll of tape. The clip is there so that one can store the food coloured ammo without making a mess.