As mentioned in passing in other posts, I bought a Smith & Wesson R8 revolver about a year ago that I have basically been using for messing around with OSR and low-light shooting. Reloading 357 Magnum (at 38 Special pressures) is a good excuse to use leftover powder that I am uninterested in stocking longterm (Bullseye, Unique, etc.). Nothing wrong with that, but as any reloader can tell you, swapping out calibers on a progressive press is typically an annoying affair. I also find that 9mm moonclips typically work much better than 357/38 moonclips due to cartridge length. You can see where this is going: I like the R8 in 357 Magnum, but I’d like it a lot better if it were in 9mm.
While .357 Mag and 9mm don’t share exactly the same bullet diameter (.357 vs .355), it’s typically close enough that you can get away with using 9mm bullets in a .357 Magnum bore. Even better, you can even have 357 Magnum cylinders rechambered for 9mm (with moonclips). So this is technically a very straightforward process.
But… if you don’t want it to be a one-way trip, you need a second cylinder. Preferably a second NEW cylinder, which will (theoretically) need to be fitted to your revolver, because as we have all heard, revolvers are all hand-fitted masterpieces. This is where things get exciting, because sourcing new R8 cylinders is tough. S&W has a lot fewer spare parts on hand than you’d think, and most of them are reserved for repairs, not gunsmithing adventures.
The obvious answer is “buy a used cylinder”. If you read random internet forums, you will be cautioned that this is an awful idea that is totally unworkable. Cylinders are married to particular guns, and a cylinder swap will get horribly out of time gun that will explode in your hand. Strangely enough, those same forums will tell you that even the S&W Performance Center lines have minimal-at-best hand-fitting.
I decided to roll the dice, and bought a used R8 cylinder and crane off eBay. They looked like they had minimal use, and I figured this might be helpful if a professional gunsmith had to retime it (which, to my understanding, is pretty doable in a pinch). The cylinder assembly came in, I marked it so I wouldn’t lose track of it being the spare, and it was time to test it.
Fitment test… perfect. Dropped right in.
Timing test… perfect. The cylinder was in front of the firing pin way before the hammer fell, and every chamber was centered right on the barrel.
Lockup test… perfect. Cylinder was nice and tight.
Live fire test… perfect. No leading in the forcing cone (checked with a Lewis Lead Remover), and it was functionally perfect.
Basically, the thing everyone on the Internet tells you won’t work worked absolutely fine. On one hand, someone’s gotta win the lottery eventually, and perhaps it was me this time. On the other hand, it’s the year 2023, and CNC machine accuracy has made hand-fitting much less of a thing, even for revolvers.