.22 magazine question

[bronco]

I just bought a Ruger 22/45, and as I was looking at it, it occurred to me "how come no one makes a .22 with a double stack magazine?" Is it a mechanical or legal issue? It would be nice to have a .22 pistol with a 20-30 round magazine.
Any thoughts about reason?

John

[weldermyass]

The rim is the problem