Get a second cylinder, then you can shoot both cartridges in the revolver
I have lost track of when I did this Model 34, but it is at least two decades ago.
Right now I am looking for a second cylinder for my 617 to make it a convertible. I would love to use one of the 8 shot 22 Magnum cylinders from the 648s
Pressure vs. bore size is a non issue.
In fact, when shooting lead projectiles, accuracy is much better shooting a larger projectile in the tight bore vs. shooting a smaller projectile down an over-sized bore.