S&W 640 pro 9mm convertible?

[Waz]

I saw someone listing a 640 pro for sale and is including a spare cylinder that he had planned to have bored out and rechambered for 9mm

I know ruger makes single action convertibles, never even occurred to me that is could be done to other revolvers.

Has anyone tried or even heard of doing this before?

 

[inkd]

I saw someone listing a 640 pro for sale and is including a spare cylinder that he had planned to have bored out and rechambered for 9mm

I know ruger makes single action convertibles, never even occurred to me that is could be done to other revolvers.

Has anyone tried or even heard of doing this before?

Yes. TK Custom will take your existing cylinder and convert it to fire 9mm with moon clips. Since it is a moon clip conversion he is still able to fire the rimmed .357/.38 in the same cylinder.

One problem with having a spare cylinder, or potential problem, is the timing. Just because it is the same model and caliber does not mean that it will time correctly.

If he is going to have it done on either cylinder, tell him to be prepared to have a gunsmith fix the timing.

 

[Waz]

Yes. TK Custom will take your existing cylinder and convert it to fire 9mm with moon clips. Since it is a moon clip conversion he is still able to fire the rimmed .357/.38 in the same cylinder.

So the cylinder conversion would allow you to shoot 9mm/.357/.38 without needing to change anything else?

Googled TK Custom and it looks like $375 for the conversion. Could be worth it if it works!

 

[aaron.foulk]

So the cylinder conversion would allow you to shoot 9mm/.357/.38 without needing to change anything else?

Googled TK Custom and it looks like $375 for the conversion. Could be worth it if it works!

The converted cylinder would do 9mm only. The other stock cylinder would do .38/.357. The trick is getting both fitted correctly without having to change the hand every time. By the time you get it working, you might be financially better off with a second gun like the 9mm LCR.

I really wouldn't think it would be the effort to swap back and forth.

 

[inkd]

The converted cylinder would do 9mm only. The other stock cylinder would do .38/.357. The trick is getting both fitted correctly without having to change the hand every time. By the time you get it working, you might be financially better off with a second gun like the 9mm LCR.

I really wouldn't think it would be the effort to swap back and forth.

The conversion that TK Custom does allows you to shoot all three cartridges out of one cylinder.

 

[inkd]

So the cylinder conversion would allow you to shoot 9mm/.357/.38 without needing to change anything else?

Googled TK Custom and it looks like $375 for the conversion. Could be worth it if it works!

Yes. You would be able to shoot all three out of one cylinder.

It is pretty cool and I do like the concept but after a friend of mine had his done, and talking to a gunsmith teacher at Montgomery Community College in Troy, North Carolina who worked for Hamilton Bowen for about 5 or 6 years, I wouldn't do it.

My friends revolver was way out of time after he got the conversion done. I took it with me to the school for Mark Dye's one week Smith and Wesson revolver class to re-time it. Mark said he could count on one hand with a few fingers left over, the revolvers he saw in Hamilton Bowen's shop that was as bad as my friends. It took me quite a while to get is straight again.

One thing we noticed was the ratchet teeth were all uniformly cut, rounded over. If you watch the video of them doing the moonclip conversion, you can see the end mill contacting the ratchet teeth, which screws up the timing.

Another thing that was brought up was the cutting of the ejector star. It has to be cut down the thickness of a moonclip, .010" I believe, in order for the moon clip to sit flush. If you shoot some high power .357 or even .38spl+p and the cases wind up sticking, the ejector star may break if you have to give the ejector rod a knock to dump the empties out.

I couldn't tell you of any documented cases of that happening, but when someone who spent the first 5 years of their gunsmith career building 1911's at Clark Custom and then the next 6 years working for Hamilton Bowen gives me advice, I tend to listen.

Theoretically, you could send the extra cylinder in to be done, install an over sized hand and time both cylinders to the new hand. Then it would be nothing but swapping cylinders to shoot a different caliber.

For a gunsmith experienced in timing Smith and Wesson revolvers, it wouldn't be an outlandish job, just research your gunsmith before you get the work done. There is a fine line between oh shit and attaboy on ratchet teeth.

 

[aaron.foulk]

The conversion that TK Custom does allows you to shoot all three cartridges out of one cylinder.

Not really. Once it's cut for 9mm, the .357 brass will fire form to the new chamber and will be pretty much done for any other .357 chamber. If that's acceptable to you, then fine. I wouldn't do it. Out of curiosity, did Tom recommend this or was it something you found on his website?

 

[inkd]

Not really. Once it's cut for 9mm, the .357 brass will fire form to the new chamber and will be pretty much done for any other .357 chamber. If that's acceptable to you, then fine. I wouldn't do it. Out of curiosity, did Tom recommend this or was it something you found on his website?

We haven't had a problem with it yet, but the loads are pretty light.

Before my friend sent it off he chewed on Toms ear quite a while about the ability to shoot all three calibers out of the same cylinder and was assured it would work. He wouldn't have sent it away if he wasn't able to shoot .38/.357 out of it.

 

[aaron.foulk]

Interesting. I find it pretty telling that he doesn't make that claim on his website. Best of luck with that. Buyer beware, I guess.

 

[inkd]

Interesting. I find it pretty telling that he doesn't make that claim on his website. Best of luck with that. Buyer beware, I guess.

I saw that too. I guess I will have to contact him and ask him myself. I don't think my buddy was bullshitting me, he is the most attention to detail, nitpicking double check three times guy I've ever met.

I'll have to satisfy my own curiosity though now.

Personally I wouldn't do it just for the reasons that I stated earlier. I am not thrilled with the ratchet star having to be cut down or the reduced thickness of the ejector star.

 

[aaron.foulk]

Understand that I'm not calling BS on anyone, here. I just think there were probably some risks discussed between Tom and your friend and your friend chose to assume them and experiment. They are slight, I'll admit, but I think there's a liability issue in claiming a .357 cut for 9mm is a legit 3 caliber gun.

For what it's worth, I know some competition guys that use .38 Short Colt in 9mm chambered revolvers. They let the brass fire form and then resize it with a 9mm die after that. Again this is a caveat emptor situation.

Let me know what Tom says.

 

[Waz]

Interesting. I find it pretty telling that he doesn't make that claim on his website. Best of luck with that. Buyer beware, I guess.

He does say the 45acp conversions will still work with the original rimmed cartridges but doesn't say the same for 9mm. That could be telling

I'm still intrigued by the idea and still might try it with something a little more "disposable" after I gather a good bit more info (and funds)

I remember reading a short article on the Medusa revolver and how it could handle 25 or so different but similar calibers. I'd be happy to get one of my guns to work with 3!

 

[inkd]

He does say the 45acp conversions will still work with the original rimmed cartridges but doesn't say the same for 9mm. That could be telling

I'm still intrigued by the idea and still might try it with something a little more "disposable" after I gather a good bit more info (and funds)

I remember reading a short article on the Medusa revolver and how it could handle 25 or so different but similar calibers. I'd be happy to get one of my guns to work with 3!

I did find a disclaimer about .38/.357 brass fire forming and sticking in a converted cylinder on Pinnacle High Performance website.

He states that they will shoot but will most likely stick.

I would be willing to bet that is what my friend was told when he sent his in. All I can say is that in several hundred rounds of .38spl, he has not had one stick. It may be because he loads them pretty light.

http://pinnaclehighperformance.com/cylinder-work/

He does make mention on this page about fitting another cylinder to a Smith and Wesson revolver for conversions.


Nothing against TK Custom but I would go with Pinnacle if I was having this done and send him the entire gun so he can make sure everything is perfect with it before it comes back. Unfortunately, he is a one man show and that would probably mean a wait for the work to be completed.

 

[Magnumite]

Timing an extra cylinder is reasonable, though costly. I would have the cylinder, ejector (ratchet), rod and complete assembly built. This would make timing the extra cylinder much simpler and effective. Back in the Action pistol days some K frame S&W revolver shooters used spare cylinders instead of speed loaders. They had to relieve and polish the rivet so the cylinder assembly would come out but it was fast.

The biggest fly in the interchangeable cylinders is changing the cylinder. Crane would have to be removed then the cylinder. Buying a second crane retaining screw so the original is kept pristine would be prudent. Assuming the cylinder, ejector, rod assembly was built the whole assembly could be swapped on the crane after removal. I am assuming the cylinder on the J frame is retained as on the larger revolvers.

 

[Minuteman]

There is another thread on this topic, maybe years ago.

I'd love a gun that could reliably and accurately shoot 9mm, .38, .357; but as I recall from our old discussion, this isn't viable, and at the cost of the conversion, better off just buying a dedicated second 9mm revolver.

I'm waiting for Ruger to make a 3" hammered version of their LCRx revolver in 9mm. Has a slightly longer grip than the snubby version. They make it now in .38. If you too would like one of these, go to Rugers site, and email their CEO, if enough of us ask, Ruger will do it, or bump up their timeline if they already plan to do it.