i found out i wasnt the first guy to make my design and im getting swamped with emails so im just gona give the link to his site http://www.yakman.i8.com/paintball.htm
dont kno but i am attempting to make one thats purely homemade-no paintball gun base- tho this requires finding a material that can withstand the pressure
i have made a co2 nerf gun it blows up reg darts but it luanches stefans easily 150ft the only prob is it could easily put an eye out so u need eye protection and dont use indoors. u can email me at vbfireball@aol.com or elitehaloforce on aim for plans on how to make it. it only costs bout 27$ and is a sick loser rifle. i live in long island and if there r evey ne wars out here ill bring it