S&W Cylinder Interchangeability?

[VanGoghComplex]

Hello! I have a S&W 686+ with an unfluted cylinder, and another gentleman on this forum has one with a fluted cylinder.

I'm curious as to whether we would be able to easily swap cylinders (easily meaning without the services of a gunsmith.) We are discussing a trade, but others on the trading forum have kindly noted that I may have been making assumptions about the cylinder interchangeability.

If this trade would require a gunsmith, does this mean that I would need a gunsmith even to install a brand new cylinder?

Thanks for your time.

 

[BBBBill]

Cylinder assemblies are individually fitted to the frame/barrel assembly. You might get lucky and have it drop in with everything within spec for that assemblage of parts. Then again you might chase your tail for months trying to get end shake, cylinder to barrel gap, headspace, and timing correct. Without the knowledge, skills, and specialized tools you're rolling the dice in a rigged game.

 

[Old Fuff]

The above information is correct. At Smith & Wesson cylinders are fitted to a particular gun. While everything may go together without issues it's a pure coincidence if it happens.

 

[VanGoghComplex]

Okay, I'm a little confused. I contacted Smith and Wesson today about this, and they told me about the same thing, but they said:

The cylinders themselves are machined with tight enough tolerances that they should swap easily and with no hassle. However, the ratchet (on the back of the extractor star) is custom cut for the hand of every revolver, so a new one would be needed.

This confuses me. Isn't the extraction star its own piece? Couldn't I keep my star, he keep his, and we just change cylinders? Or is it not that simple?

 

[MrBorland]

Couldn't I keep my star, he keep his, and we just change cylinders? Or is it not that simple?

The fit between the extractor and the recess in the cylinder that it sits in is a pretty close fit. It's not a given that they'll swap between cylinders. Also, the shape of the recess has changed over time, so a new "square" extractor won't nohow fit in a cylinder with an older cutout.

I'm thinking the easiest way to proceed would be to swap the entire cylinder/extractor assembly, and have a 'smith (or S&W) fit a new hand and/or stop bolt.

 

[BBBBill]

VGC, the same answer applies to swapping an ejector as for the whole cylinder assembly. Just because they have improved machining tolerances for components doesn't mean that detailed fitting is no longer required. The ejector/ratchet would still need to be checked for fit to the cylinder, the center boss fit to set headspace (can't do that if it has already been fit with a specific cylinder/frame and is now too short for the new frame), and the individual ratchet pads fit to the hand. (frame window position/width and hand thickness may prevent proper fit of an already fit ratchet).

 

[Old Fuff]

Your question is one that no one can answer - even Smith & Wesson.

What you propose to do is remotely possible, but not probable.

The only way to find out is to try it and see.

And the chances that the switched cylinder assembly's will work in both revolvers after making the trade is even more unlikely.

Any of the top quality/fitted revolvers regardless of make or model are usually not amenable to part switching.

 

[RJTravel]

Easy solution - swap handguns.

 

[VanGoghComplex]

I appreciate your answers, and understand better now.

Thanks for your help, all.

 

[Gaucho Gringo]

In other words even in today's world of interchangeable parts which are supposed to be interchangeable are not. Didn't Eli Whitney have this sorted out in the 1830's when he did his bunch of parts and assembled a usable gun using random parts in front of a government committee?

 

[rcmodel]

Why, yes he did!

But it sure wasn't a revolver!!

rc

 

[Old Fuff]

Not quite. The parts were close enough so that they usually could be hand fitted.

Colt's famous model 1911 .45 pistol wasn't fully interchangeable until late 1944. You will find that prewar examples often have the slide numbered to match the frame.

Smith & Wesson claimed that the Army tested the M1917 by fully disassembling several revolvers and then successfully reassembled the parts into functional guns, but they're is a difference between "functional" and "precisely fitted."