I have seen them work before but you have to work on a weird finger skill, and I think it would be almost impossible to stay on target with the amount of finger twiching you have to do. Plus look at the weird way you have to hold the rifle.

Check this one. It is just as junkie.
I get a kick out of this one. A friend of mine put one on is 10/22 and used it at an indoor range once. You should have seen all the heads pop out from around their lanes to see what the hell was going on down on the end lane. I think I remember seeing, at the last Tanner Gun show I went to, some guy had built a kind of gatling gun by putting 2 10/22 together with one of these crank triggers operating the 2 of them. Some folks have too much time and money to waste, I guess.

http://www.cabelas.com/cabelas/en/te...FCcat20803.jsp