.....as far as I know, Mag na port will cut slots in your RG 22 revolver if your willing to pay the freight.
You have several options for porting, including an add on muzzle brake, a boss system, etc. that can all be done by a competent gunsmith.
The trade off with a ported barrel is as is always was.....the same as your pistol, you get some perceived relief from recoil, some degree of muzzle flip control (moot in a single shot rifle) BUT... you also get markedly increased report directed at the shooter as well as your range companions.
JMH2¢
BT