IMO, if you havea good feel for the rifle in it's "natural" caliber then I see no reason why using a 22 conversion to help practice your movement and timing would be non beneficial. Sounds like a good idea to me although I would certainly mix in hitting the course with the caliber you would usually take into combat. That would only make sense.
Firefighter/EMT - Currently teamed on Engine 1... I always get to play with my Knob!
"Good judgement comes from experience and experience comes from poor judgement" - Unknown.
"An armed society is a polite society. Manners are good when one may have to back up his acts with his life." - Robert A. Heinlein