I have a S & W model 63 and I was amazed how fussy it was about ammo. Several brands would have the brass back out a bit from the chamber and would prevent the cylinder from rotating.

So, your revolver may have something to say about what you feed it.

But I would be disinclined to carry any rim fire gun as a back up. Of all the ammo I've ever shot, the rim fire has been the least reliable. They rely on centrifugal force to get the primer in the rim--not a perfect process in my opinion. Pretty good, but far less reliable than any center fire ammo. I'd rather carry a .32 from Keltec than a .22 revolver.