Converting a Revolver to 9mm...sort of...

[Oyeboten]

Something I've always wanted, but which was never made and offered when they should have been, is an early S&W 'M&P' chambering the .38Auto Cartridge, with Moon Clips.


Or...a late '20s 'M&P' chambering the same-size, but peppier .38 Super Cartridge...


Now...in your opinions...knowing I will predominately shoot only plain Lead, would the Barrel of either of these manage to handle their respective Cartridge's pressures alright? If for occasional full 'Standard' Power Rounds, and usually under-loaded 'plinking' rounds?


And...Cylinder-wise, if I were able to convert say, a newer, K-Frame Cylinder from say, a .32 Magnum, having it re-bored and so on, for correctly chambering the .38ACP, or, .38 Super Cartridges? So the Cylinder would be strong enough..?


Any thoughts?


Phil
Las Vegas

 

[9mmepiphany]

wouldn't it be easier...if not cheaper...to just start with a M-547 chmabered in 9mm.

...and i don't think it's been that long since i saw a M-627 chambered in .38 Super...i think S&W uses the N-frame for presure reasons

 

[Oyeboten]

It would be an entirely different aesthetic...


What I always wanted to have, is the 'M&P' Revolver S & W should have made in 1902, or 1906 or so, for the then new or newish .38 Autocolt Cartridge...or, a stouter alloy late '20s version for the .38 Super...not a modern Revolver.


I could live with a Modern-ish, 1970s or 1980s Cylinder which appears identical to an 'M&P' Cylinder anyway...but, that would be the limit...


I'm fairly sure an older/early 'M&P' Frame and Barrel would be fine with .38 Autocolt, especially 'Lead' insead of Copper Patch...but, the Cylinder might not...or, the Cylinder from a period .38 Special would have too long a primary bore, anyway...though a period 32-20 Cylinder could be re-bored...if it were still then strong enough...and it might not be.


.38 Super pressures of course are a lot higher than .38 Autocolt...so, I doubt any period S & W K-Frame Cylinder would stand it very well...hence, wondering if a newer .32 Magnum K-Frame Cylinder, once re-bored, would..


I'd be happy for regular plinking, to re-load .38 ACP to basically standard .38 Special Pressures...while having then the option for SD or other, to shoot full 'Standard' Power, Factory .38 AcP, or...maybe, if possible,.38 Super...


An 'N' Frame would definitely be a better candidate for any normal diet of .38 Super...but, is not what I'm after.



Imagine an 'earler' realization of what the Model 10 .357 Magnum was...only milder, and in .38 Autocolt...or possibly .38 Super





Phil

 

[Oro]

It would be an entirely different aesthetic...

My first thought was the same as 9mmepiphany - start with a 547. I don't see how the aesthetic is different; The cylinder is the one part on a modern K frame you can't tell from the old ones...

Really, It would be cheaper and more practical to chuck the moon clip idea and use that slick-as heck ejector system on the 547. Plus, as it's heat treated for 9mm pressures already, it's going to tolerate .38 super just fine. A rebore is all that's needed.

 

[Oyeboten]

Well...hmmmmmmmmmmmm...maybe a 547 Cylinder could be modified, and relieved for the use of Moonclips, IF it had a shorter 9mm appropriate stepped Bore to begin with, needing only to be lengthened...and, I'd heard they did not...that they were very un-caring about that, and bored them straight through with no 'step'...so, while it probably would work...it'd be sloppy...or, as sloppy with .38 ACP as it already is with the shorter 9mm.



Is that correct?

Were the 547s Cylinders bored straight through with no 'Step'? Or....were they 'stepped'?


If they were 'stepped'...I'd consider it a good prospective candidate..!



I want 'Moon Clips'..!



Lol...

 

[tekarra]

OMG, do you really want to destroy a 547?
May I suggest you visit www.smith-wessonforum.com. Some people there have chambered M&Ps to several rimless cartridges.

 

[earlthegoat2]

This is where we have to stop posting and just let things play out as they may.

 

[Oro]

IF it had a shorter 9mm appropriate stepped Bore to begin with, needing only to be lengthened...and, I'd heard they did not

You know, I don't know. I've only ever handled one 547 in my life and I didn't check that detail. but wrecking that extraction system would be a waste (e.g., you REALLY want moon clips...)

How about sending a Model 19 cylinder to Bowen for the conversion, then fitting it to the frame you want? You wouldn't have the step, though.

 

[Jim Watson]

I dare say you could do it... if you could do it, or pay for it.
Finding a K32 or even K22 cylinder would be the first problem. Hamilton Bowen has about used up the world supply and has started making his own S&W cylinders to be chambered for odd calibers. He really likes the .327 Ruger Magnum but might could be persuaded on a .38 Super. For a price. A LARGE price.

Cutting up a 547 cylinder would be a problem. In the first place, although they were not "uncaring" enought to bore the chambers straight through (How would the rimless, clipless rounds headspace?), the 9mm has a larger head diameter than .38 Super and would yield an oversize chamber at the rear. Not much, but there.
The real problem would be chopping into the patent 547 extractor. There is no star as such, and there are a lot of moving parts in the hub under the rachet.

There are shops - Pinnacle Guns that I know of - that will rechamber a .357 magnum cylinder to a multicaliber rig firing 9mm P, .38 Super, and 9x23 Winchester. Naturally there are bullet jump and throat diameter mismatches, but it might be worth asking for user references to see if it really works. I think your best bet would be to have this alteration made on a late production Military & Police Model 10 with tapered barrel and heat treated cylinder that would give you the look you want and reasonable durability.

I doubt a reputable gunsmith would rechamber an old .32-20 cylinder on your sayso that you would only shoot .38 ACP. A fit of enthusiasm or a gun trade could get it loaded with Supers or even 9x23 that would demolish it.