S&W Mdl 10 Conversion To Pseudo Mdl 547

Mr. Mosin, FWIW I had a .357 L-Frame cylinder converted to 9MM by Pinnacle. Just a comment reference using the original .38 Spcl. ammo in the 9mm conversion. I have only tried one type Federal .38 +P I had on hand in my converted cylinder. One case split. Also tried a cylinder of factory .38 Super, again, a case split. While other types of .38 Spcl. and .38 Super might not split cases, I don't consider casual use of .38 Spcl. or 38 Super desirable in my particular conversion. With the 9mm and moon clips, 9mm ammunition worked as it should, no pierced primers, sticky extraction, extraction, etc. I don't have any plans to try .357 in the converted cylinder, and in future intend to stick to the 9mm cartridge for which I had the cylinder converted.

If I had a K-frame .38 converted, barring exigent circumstances, I'd plan to just use the 9mm ammo.....ymmv

fxvr5 said:

Gee, I don't know. I guess a person could go to their website to find out.

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I guess you could. I did, about 5 seconds after I posted, to make sure it was still in production and not some super rare unobtainable thing.

I think the last few posters have made it clear that once you convert one of these guns to 9mm its pretty much a 9mm only from now on. Its already been said but if you want a 9mm then just buy one set up that way from the factory.

ThomasT said:

I think the last few posters have made it clear that once you convert one of these guns to 9mm its pretty much a 9mm only from now on. Its already been said but if you want a 9mm then just buy one set up that way from the factory.

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Accordingly to TK custom with their 9mm conversion of 38/357 revolvers, the revolver retains the ability to shoot 38 Special (and 357 Mag if it was originally a 357 Mag). TK does stipulate that pressures for all cartridges must not exceed 34-35 ksi (such at 9mm +P).

https://tkcustom.com/services/machining-sw

TK does great work. You can trust Tom to make you a great shooting 9 mm Model 10.

mcb said:

Accordingly to TK custom with their 9mm conversion of 38/357 revolvers, the revolver retains the ability to shoot 38 Special (and 357 Mag if it was originally a 357 Mag). TK does stipulate that pressures for all cartridges must not exceed 34-35 ksi (such at 9mm +P).

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Yes I understand that. I have no interest in a 9mm revolver. To me it would ruin a perfectly good gun. I like a model 10 as a 38 special and have never ever liked moon clips. Others do but not me. Besides its just another fantasy thread for the OP who is full of gun fantasy's that will never happen. I hear about them all the time in the emails we trade.

Mr. Mosin said:

If I can ever get back to work, and sock back another grand or so, it’s gonna happen.

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I truly hope you do Dan. But I would still recommend a gun built from the first to be a 9mm and not a conversion. I think you will be happier with it.

Mr. Mosin said:

If I can ever get back to work, and sock back another grand or so, it’s gonna happen.

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That’s the spirit!

Mr. Mosin said:

Apprentice carpenter, and this apocalyptic weather has me out of work... for three months now.

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Where do you live? Here in MI, nothing stops or even slows down construction. Sure as hell not for 3 months.
Not heat, cold, snow, nothing. Maybe lightning but only until it passes by.

Myself I'd be trying some 38spl p+ loads using 110gr, 120gr, 125gr, 135gr, 147gr bullets and see where the poi is compared to where the fixed sights are pointing.

Typical fixed sighted revolvers setup to shoot 38spl ammo have sights for 158gr bullets. You might find that the lighter/faster bullets shoot low at closer ranges.

Ruger SP101 comes in 9mm, although it is a 2.5" barrel. I have rented one a couple of times while considering getting a 9mm revolver. A decent gun to shoot, albeit somewhat snappy.
My older grandson is an apprentice carpenter in Minnesota. It is a formal, state certified apprentice program. He hasn't had any time off that he didn't request for the last 2 years.

Mr. Mosin said:

MS. Can’t roof in the rain, and it rained for ~80 some odd days straight

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Sounds like you and your carpenter friend should have went into the Ark building business.

Illustration for my previous post (the edit window was closed).


9mm Luger cartridge.
9mm Luger casing fired in a 9mm Luger chamber.
.380 ACP cartridge.
.380 ACP casing fired in a 9mm Luger chamber.

Mr. Mosin said:

I had a crazy idea... take a Mdl 10, ship it to TK Custom to have em machine it for 9x19mm with moonclips. Not *me* doing it, just an idea I had.


Also, in (say a 9x19 moon clipped Mdl 10) could you run .380 Auto in the moonclip too ?

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The israelis did something like this back in the late 40's. Except they used WWII model 10's that had been chambered in .38 S&W. Seems like the difference in bullet diameter .355 vs .357/.358 was enough to lower the pressure to reasonable levels

They made a few from scratch, too; 50 or so in 1951-52.
Here is the auction where a presentation version sold for $18,400.
https://www.rockislandauction.com/detail/59/1817

There are several references there and elsewhere saying it is "based on the US 1917." That must mean its use of half-moon clips because the proportions sure look more like M&P K frame.

Sarge7402 said:

The israelis did something like this back in the late 40's. Except they used WWII model 10's that had been chambered in .38 S&W. Seems like the difference in bullet diameter .355 vs .357/.358 was enough to lower the pressure to reasonable levels

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The 38 S&W uses a .361" bullet.

At one time Korth was developing a 9 MM conversion cylinder for S&W L frames. I saw a video of it but do not know if they were ever offered for sale. I would like to have one.

fxvr5 said:

The 38 S&W uses a .361" bullet.

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Present groove diameter spec is .3595". We need somebody to slug a bunch of BSRs to see if some Special barrels crept in.
I have read of stuck 178 gr FMJs after the English got scared that the French and Germans might say a 200 gr LRN was too naughty. There are reports of revolver barrels counterbored past a bulge but none on display that I have seen.

hannstv said:

At one time Korth was developing a 9 MM conversion cylinder for S&W L frames. I saw a video of it but do not know if they were ever offered for sale. I would like to have one.

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Lots of discussion about 5 years ago, but it petered out 3 years ago with no shooting report that I saw.

The P&R Medusa multi-caliber revolver was preceded by a cylinder for S&W.

fxvr5 said:

The 38 S&W uses a .361" bullet.

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Very true. I'd forgotten that small fact. Makes a good bit of difference as a bit of the expanding gas would have blown by the base of the bullet before it got a chance to expand to fill the bore