Rechambering Stainless S&W K-Frame

[E-Rock]

I know this has been discussed with regard to model 10s, but I wonder if the same metallurgy concerns will be raised with stainless k frames.

I have an opportunity to pick up a NOS model 66 cylinder and 2.5" barrel for a very reasonable price. I also have a late 1990's 4" model 64 that I would like, if possible, to convert to .357. The cost of the parts, labor, and model 64 come out less than the price for 2.5" model 66s that I've seen, so the cost barrier is avoided.

The new barrel would relieve the forcing cone gap concerns that have been raised with just converting the cylinder.

Unless I'm missing other concerns, the only barrier left would be the strength of the 64's frame when firing .357 loads. I don't know if stainless undergoes the same treatment as the steel in model 10s. I also don't have a K magnum frame to measure and compare with my 64.

I realize it would essentially end up with a 2.5" model 66 stamped model as a model 64 (or, more likely, just a bastardized model 64), but I'm intrigued by the thought of essentially arriving at one of my "dream" guns at a substantial cost savings. I also remember reading somewhere (probably here) that some VERY early model 64s had been chambered for .357 in a special order.

Let me know if I'm on to something here or if I should abandon the idea and be happy with my safe, reliable, and ultimately adequately potent, albeit slightly anemic, model 64.

*Another question: if .357 is a no-go, would swapping out the 64's 4" barrel for the 66's 2.5" barrel pose any problems?

 

[LawofThirds]

Swapping in a barrel doesn't fix any of the forcing cone issues of the .357 in the K frame. You're still going to have the thin spot on the underside of the forcing cone that is the weak spot.

Honestly, I would suggest looking into some of the stouter .38 +p loads and keep a lovely gun just the way it is.

 

[Brian Williams]

Until you swap the barrel, $125 to install the barrel, and swap the cylinder, $50 to fit the cylinder, you are half way there to purchasing a new to you model 66.

 

[Lucky Derby]

The 64 is a fixed sight gun and the 66 has adjustable sights. I think you would either have to do some major mods to the front sight or install a new rear sight to get something close to working together. Yet another cost. Frankly I don't like the idea of converting a .38 to .357. It may work and then again it may not. I know I do not want to be the one pulling the trigger to test it the first, tenth, hundredth, or thousandth time.

Law ofthirds, I think he was talking about the shorter forcing cone on .357 guns as opposed to the .38 guns with shorter cylinders. I don't think he was referenceing the K frame .357 weak spot on the forcing cone.

If you swap either a barrel or cylinder, the gap needs to be reset, even if you stay with .38.

 

[dfariswheel]

Unless it changed in the later years, the "K" frame .357 revolvers were given different heat treating for use with the far hotter .357 round than the lower pressure .38 frames and cylinders.

I can assure you that S&W will tell you that a .38 "K" frame is absolutely NOT suitable for use with the higher pressure .357 cartridge.

People look at guns like the .38 Special Model 64 and compare them to the .357 Model 65 and assume that since they LOOK just alike, S&W is cheating the buyers by using the same frames and cylinders on both and just charging more.
The reason the Magnum guns cost more is because of the heat treating. Since you can't see heat treating, people assume you can re-chamber or re-cylinder a .38 revolver to .357.

Next, no reputable gunsmith will touch something like this, so who's going to fit the barrel and cylinder?
Barrels and cylinders are very much hand fitted parts and require hundreds of dollars in expensive tools to do the work, starting with a lathe to fit the barrel and either a milling machine or a precision surface grinder to fit the cylinder to the frame.
Used parts have already been fitted to a different frame, and don't just "drop in".

Swapping the Model 66 barrel itself would still require the special barrel vise and frame wrench with "K" frame inserts and the lathe, and the special cutter tools to reset the barrel/cylinder gap and recut the forcing cone, but it could be done.
Problem is, you're going to have a front sight and ramp FAR too tall and cutting it down would leave you with not much front sight.
Doing it right would require machining the sight off and the ramp down, slotting it, then fitting a new front sight.

All this is do-able, but won't be cheap.

 

[ironhead7544]

Get some Buffalo Bore or Double Tap ammo for your 38 Special. Changing barrels will get too expensive.