Revolvers: SA: Ruger Single Six, or some of the old Colt$ if you can find them. Both of these, & several other SA models, had two interchangeable cylinders. I've owned a Stainless Steel Super Single Six(lotta S's, huh?
) for many years.
DA: S&W once made a J-Frame .22 Magnum Kit Gun, Magnum cyl only.(a *Very Few* were made with interchangeable .22 LR cyl/crane assemblies. As you might imagine, they were *Eck-$pen$ive, & had poor sales). Bill Jordan himself used to carry a .22 Mag S&W J-Frame as a backup gun. Several other DA revolvers were made in .22 Mag, by mfgrs like High Standard, Charter Arms, H&R, & even some of the old cheapie makers like Iver Johnson.
Rifles: both Marlin & Savage still make .22 Mag bolt action rifles, I think. If not, there should still be plenty of used ones out there. Marlin had "clip" & tubular magazine versions of the same rifle. Way back when, Winchester made their old hammerless model 61 .22 pump in .22 Mag for its last few years, but rare & $$ today. Both Marlin & Winchester made several other rifles in .22 Mag, look 'em up, including a hammerless lever action from Win at least, maybe from Marlin too.
Maybe the sweetest rifle of all in .22 Mag- the Winchester 9422 Magnum. Discontinued last I knew, but quality all the way.
The Savage/Stevens .22/shotgun over-under Camp Gun had a version chambered for .22 Mag, over a 20 Ga shotgun barrel.
I think the current Henry .22 lever actions offer a .22 Magnum version.
Best bet for a cheap used .22 Mag rifle- probably a Marlin, Savage/Stevens, or Mossberg bolt-action(or the house brands made by them). They were made for decades. Scour the pawn shops. A late model Marlin, with stainless steel, synthetic stock, & tubular magazine would be at the top of my list, your list may vary.
Coolest combo- probably a Win 9422 Mag & a Colt convertible SA. Next coolest, same rifle with the Ruger SA.
(I'm willing to settle for my own combo, the Ruger Stainless SA & blue-steel Win 9422 .22LR.)
.22 Mag factoids:
1. Shortly after its introduction, the .22 Magnum cartridge was almost discontinued. The only thing that kept it alive were the sales of Colt & Ruger SA revolvers with convertible cyls.
2. Revolver ballistics- a .22 Mag from a ~6" bbl revolver shoots a *little* stronger than a good .22 LR HV from a rifle. With hollow-points, the Mag shoots a full 40 grain HP bullet(~1200 fps real world) while most LR's are 36-37 grains(~1200 fps).
3. Sadly, it seems ammo quality has declined, just like .22 LR.