Meanwhile, here's what my .22 Disco can manage vis-a-vis 60shots from one fill.
http://www.network54.com/Forum/581291/thread/1213837036/60+shot+.22+Discovery+string-+1084fpe+total+muzzle+energy+-+8.4bar-cc-fpe
Here's the same gun fitted with a .177 barrel.

Steve
To summarize, we conclude that the Second Amendment protects an individual right to keep and bear arms.
SCOTUS Columbia v. Heller 6/26/08.