Treedog, yep, they used to make them. You can still find them at gun shows, if you're willing to part with about $150.00 for one.
Oops, mistake there. The 50 round mags run that much. You can pick up 30 rounders for about $100.00. I bit the bullet at one show and bought a 20 round mag for my 10/22 for $75.00. Expensive but sure made shooting it more fun.