Wanting to convert a 60-4 to 9mm - questions

[winchester62]

Edited to add, I finally got this done. 10 months later. Go to post 6 for the update....


I recently got a second cylinder to convert a model 64 to 9mm with moon clips. I had the cylinder cut by Mark at Pinnacle. He did an awesome job. I really like the conversion and I can easily go back and forth by just changing the cylinder. I'd like to do the same thing with a model 60-4 I recently acquired.

I bought a very nice extra cylinder for the model 60 and it turned out not to fit. It IS a 38 special only cylinder, but it is 1.5 mm to long. The original is 39mm and the "new" one is 40.5mm. I presume there was an interim time that the cylinder of the model 60 was lengthened, but it was still reamed only for 38?

This leads me to the conclusion that I need a cylinder from a model 60 dash 1-4 or 5 or something along my those lines. I also thought maybe I can find a cylinder from a 940 and if I'm lucky it might work without fitting as my 64 cylinder did. That one was good in timing, forcing cone to cylinder face clearance, and head spacing. Maybe I'll get lucky again or at least require only minimal fitting.

The big question is this: what is the cylinder length of the 940 no dash and dash 1 respectively? And since these cylinders don't seem to be recessed like the recut one from Pinnacle, is the frame window, and forcing cone inset the same on a 940 as a model 60? Lastly, if I need to stick with a model 60 cylinder, when did S&W change from 39 to 40.5mm? With what dash number engineering change that is.

Thanks for any help. I read a lot of old threads using the search feature but needed to ask a few questions.

 

[two-bit cowboy]

Sounds like you picked up a cylinder for a J-magnum frame, which began in 1996. Your 60-4 is 1995 or earlier.

Hope this helps a wee bit. Can't help with your 940 questions.

 

[326MOD10]

I did a measurement of my 940 cylinder and then a conversion and it appears to me to be 40.5mm.

Someone else with more precise equipment may be along soon and correct me but for now that is what it looks to be to me.

I have (somewhere) an unfluted Model 60 cylinder that I had converted by TK Customs. I had it mounted on an older model 649.

If I can find it I will let you know but think it is in storage and not sure in which box. If I get a chance I will try to go see if I can find it later this week.

 

[winchester62]

Thanks 326. What dash number is your 940?

 

[326MOD10]

My 940 is a no dash.

 

[winchester62]

So with Pinnacle not taking work anymore, I sent the 60 cylinder to TK Custom. Their turn around time was incredible. About a week from the time I sent it off.

Anyway, I've sunk way too much money into this gun buying extra cylinders that don't fit and all, but I'm glad to have it done and back in my hands. Here's a picture or two.