Friend of mine had one of the old DBM Remmy's a lot of years ago. Seems to me we were busting jack rabbits around 150 yards away pretty regularly. Nice little riflegun. 22Mag is likely more versaltile, though.
Keith, do you still have jacks up there? We were thick with them in NW Iowa until sometime around 1970 and then it was like they all packed up the kids and headed out. I don't know when I last saw one. Best, John