So I'm considering having a spare cylinder fitted for a Model 66, cut for 9mm moon clips.

Does anyone know if a older cylinder will fit the new production Model 66?

Even a pre model number cylinder can be fit to a late model frame. But, you may have better luck with a newer one as CNC tolerances are closer so less hand fitting was involved. BUT, even a cylinder from the same model and dash number may need some adjustment. The yolk tube length or depth of center hole in cylinders varies a tiny bit. So tube needs adjusted to cylinder with shallowest hole and other cylinder may need a shim. The ratchet teeth sometimes need adjusted, but I have found that to be rarer than the yoke tube deal. Also, some times the ejector rod and center pin need trimmed. You could even end up with a rod that was a bit short and have to find one that was a bit longer. Sometimes you get lucky and it all goes right together and works, often there is some adjustment needed somewhere. NOTE, a recesses cylinder would either need the recess milled off when made into a 9mm or the frame's lug would need trimmed back for the extra rear length of the cylinder.

I have made 2 K 38 cylinders into 9mm. Be aware that the only place I have found K frame 9mm clips is from TK custom at $80 for 10. They will ream and recess your cylinder and give you 10 clips for $430. There are some model n66 cylinders on Ebay right now for about $120. $550 for a 9 mm cylinder seams spendy to me. You would be 1/2 way there on the price of a 929, 986 or a 640.
here is one of 2 I did, But I already had the cylinders, a milling machine ant the rent on the reamer was $42

steelslaver

Thanks

It's just a mental exercise right now. I'm think long long term, as in certain types of ammo become almost completely unobtainable still being able to shoot revolver.

I’ve been thinking along similar lines to do a 9mm conversion on a Model 60-4. Please keep posting with your progress as I’ll need the encouragement to continue my project.
I like the original 38 Spl chambering, but I’m experiencing growing interest in 9mms, so the idea of a second cylinder fitted in that caliber is attractive. Fortunately orphan Model 60 cylinders are fairly easily obtained.
Steelslaver, does TK Custom give a break for reaming 5 vs 6 chambers?

Froggie

Looks like a J frame is the same as a K. From doing mine I can tell you that once you have the cylinder setup reaming another hole takes very little time. What is much harder to me at least, is machining the recess. You have to cut right in tight to the ratchet teeth and it wouldn't take much to nick a tooth and wreck the ratchet.
Here is their page for doing S&W cylinders.
S&W Firearms Revolver Cylinder Machining - TK Custom

You can buy a J frame 9mm for about $850.

Plus notice that TKC says for standard loads only.

The only reason I did it was I had no 9mms at all. Being as it is a very common round it seams prudent to have a gun in that caliber. I had several K frame 38 cylinders left form my J&G projects and I only needed to rent a 9mm reamer. For me the rest was just time in my shop. I had already bought 10 of the K frame clips, because I modified 2 of them to use with 22 TCM in a modified K 22 cylinder fit to use in a model 10 I had setup as a 22 Harvey Kay Chuck.

TK Custom did my 60-4 about 3 years ago. Like you are thinking, I got a spare 60-4 cylinder and yoke from the big auction house in the sky to avoid modifying the original revolver. I got lucky, and the spare parts dropped right in without any adjustments. The TK custom work was excellent, and the turn around very quick.

Be aware that S&W moon clips won't fit like the TK moon clips (I also have a 940 and wanted to use the same clips on both guns). The TK Custom clips are nicer, and load/unload easier, but are pricey.

Attached Images

20190131_133624.jpg (70.6 KB, 26 views)

Not to thread jack but you cannot drop that bait without a link to this gun somewhere to look at and learn from it.

I don't think I have ever taken a picture of it. Just a round butt model 10 fram with 1 6" heavy K22 barrel and 2 K 22 cylinders, one reamed to 22 Harvey Kay Chuck and the other reamed to 22 TCM and relieved for moon clips. As the TCM uses 223 as a parrent case it is slightly smaller than 9mm. So to uses the K frame 9mm clips I used a cutter disk in a Dremel and made a slice on each arm then slightly formed them in a bit so they grip the TCM cases. I like making things that are a bit different. If you hate Bubba, I am your worst nightmare.LOL

steelslaver, good info. Now, I'm no machinist so please humor me if this is a dumb question. I need clarification: You say that most of the work is in making the cylinder fit the yoke tube. I must assume however, that fitting just the cylinder to the recipient revolvers yoke is easer than fitting the entire cylinder/yoke assembly from the donor to the recipient frame?? Please explain.

Thanks!

BTW - I just realized that the yoke screw retention slot is different between a 66-4 & a 66-3. One is kinda squared off, the other a coned slot. hmm....

__________________
DAO Hunter, SWCA #2955

Well, it all depends on each gun, cylinder and yoke. I believe the yokes are finished mated to a frame. You might find a yoke fits nice in another frame and then again it might be a bit high or low in the front. Then the yoke tube may be a tiny bit longer or shorter or the depth of the hole in cylinder may vary. So one cylinder may or may not headspace the same. How it is all going to fit together is anybodies guess. a cylinder might go on a yoke and fit a frame perfect. It may have endshake (easy fix with shims) or it my not even close up because the yoke tube to cylinder fit is long. Heck the ejector rod might be a bit long. Like I said, I have got lucky and I have had to tinker.

The current New Production 66 is a major redesign compared to all the 66's that preceded it. They look almost identical but the devil is in the details.
Please post what you discover.