CR,
You did not specify what action or mfg. of your deuce. The 20 VT has as its parent case the 221 fireball. Some folks like Remington add a spacer in the magazine to achieve feeding.
I had a 17 mach IV in a Riihimaki, and due to the nature of the clip/detachable mag, loading could be tricky if you were wearing gloves or were in a hurry. I'd discuss the feeding issue with your gunsmith. If its a single shot like the Cooper model 21, no problem.

GWB


A Kill Artist. When I draw, I draw blood.