i do have a pneumatic, and i do use a sabot, because it gives my water shots more power i use foam that i pre-cut to my barrell diameter

how about taters??? but im building a 2" barrel gun, and i wanted to shoot atleast 1 golfball out of it, but i was looking for things i could use as a good sabot, and if u have teflon tape, if u have the same kind i got u can get part of the cover peice, trim the lip off of it and its a perfect fit, may want to put 1 layer of electrial tape for airtight fit, but i cuit it all out and now when i get my gun finished itll work perfect, just got to cover the big center hole in the peice with some plastic wrap or something

It may be seasonal, but what I found that works very well. Walnuts right of the tree work great, especially if you have a barrel knife. The walnut has flesh around it. When its shoved down the barrel, excess is cut off leaving an airtight seal and a rock hard core. At 125 psi I can put one through a piece of 1/4 inch plywood.

today I took a small waterballoon, slid it into an old toilet paper tube, duct taped the back end, and I used a piece of foam rubber(pipe insulation) for a "wad" the waterballoon was protruding from the tube, and I gassed up to around 100psi, (2in air cannon, with a 36in barrel, and a 36in chamber), and it dissapeared into the trees at about 50 ft high, at 250-300 ft away, I am looking at using construction paper to "sabot" the balloon, and still use the pipe foam as a wad, I will post how it works, I just ran out of daylight today to try. if it works I am going to use it for mortaring a fortress at our paintball field here in two weeks:)
Chuck

The rounded ends off of tool handels
I generaly have to put a little duck tape around them, but they work surprsingly well

Dixie 3 oz cups make great sabots
i shoot everything out of them, dirt, water, gasoline in to the fire

Large tabasco bottles.