If you weighed something and you wanna convert it here is a site -- http://www.onlineconversion.com/weight_common.htm
Also do you guys think this "list" should include food ammo such as potatoes, any type of vegetables, fruits, etc? I think it would be complicated but I could give a close estimate of what each weight in different diam.. for example how much does a 2" potato slug weight, etc, etc.
(Sorry for my bad write up but my english writing skills aren't spectacular), but you get the point of the thread

Also in addition to the weight, if you want, you can give the diameter of the ammunition in (preferably) inches.
List of spudgun ammo:
6mm airsoft BB (.25 gram)- .008818 oz.
6mm airsoft BB (.12 gram)- .00423287543 oz.
6mm airsoft BB (.20.gram)- .00705479239 oz.
AA Battery- .81130112484 oz. / .236220472 Diameter
AAA Battery- .40565056242 oz.
AAA Battery (lithium)- 0.26808211082 oz.
Golfball- 1.56oz.
Paintball-
Marble-
Bouncy ball-
4.5 mm BB- / .177165354 Diameter
Potato slug 2 inches-
Potato slug 1.5 inches-
Potato slug 1 inch-
Potato slug .5 inch-
Apple slug 2 inches-
Apple slug 1.5 inches-
Apple slug 1 inch-
Apple slug .5 inch-
1" Chrome steel ball bearings- 2.18698564 oz.
Store bought blowgun darts?- .0388013581 oz.
1" Superball- .388013581 oz.
1" superball= 11grams
(You don´t have to actually weight stuff... you can help out by just adding on to the list of common ammo used in potato guns)
(If this thread picks up I'll order everything up in alphabetical order to make finding things easier)