Ur description is almost exactly how a regular paintball gun works. My paintball guns don't use compressed air, but rather function like a spud gun. I've made a bolt action gun w/ a tank and a scope, and it worked beautifully (although its looks could be otherwise). As far as advancing the guns i lost motivation because i really don't play paintball. If u want to show me up and go build a semi-auto paintball gun feel free to. If u can build a functioning 1 in less than a week and on 1 trial then u truly a master. And if u can build 1 w/ the materials u have then u must do this kind of shit 4 a living, or have no realistic idea what ur talking about. But to be honest i really don't care because i only do this shit as a hobby. U've made ur point though, people care way too much about looks. If u actually paintball u would c these 4 what they r. A cheap single shot pistol.