Converting a +P airweight to 9mm

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oneounceload

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Is it feasible enough to have someone like Cylinder and Slide or Pinnacle make a 9mm cylinder for an airweight 38+P revolver like the 642? Or would it require the 357 version?

TIA
 
No really possible,

the 9mm has higher chamber pressure than the .38+ and the .357.

The frame is likely Aluminum and should not take the stretching from the higher pressure.

Why the consideration?
 
SAAMI lists chamber pressure for both the .357 magnum and the 9mm (standard pressure) at 35,000 PSI. Pressure for 9mm +P is 38,500. I would think the scandium J-frames would be marginal to convert over to 9mm.
 
That blows my mind that the "marginal" 9mikemike produces darn near the same pressure as the .357 magnum. Where are the foot pounds of energy? Lost in translation? Stuck against the case walls? I would like to see the "marginal" 9mikemike out of a 1,7/8inch barrel VS. The Speer short barrelled snub nose ammo. It's not like it's unrealistic, there are a couple companies that make 9mm revolvers.

Then again, this is admittedly not my expertise...
 
In theory, if you start with any 357Magnum gun and add a 9mm cylinder, you'll be OK.

BUT I wouldn't do it to a Scandium gun - even one that's allegedly "357".

I would be worried that the way the pressure hits might be too "different" - possibly a sharper, shorter "power stroke". The S&W "Scandium" (actually aluminum with trace amounts of Scandium as an alloying agent) guns are pretty freakin' marginal and S&W engineers just haven't tested that combination.

Would I do it with a 19oz Model 60? Sure. No problem at all. Ruger SP101, no problem. Ruger LCR357 - yeah, should work, starting to get marginal but the cylinder and primary frame are steel.

An S&W K-frame 357 snubby would be perfect - and there's a cylinder blank available (last item):

http://www.bowenclassicarms.com/Parts_Cylinders.htm

Those are retail prices - gunsmiths get 'em way less so it's not going to be too expensive overall to have 'em reamed and fitted. It'll be bad, but within the realm of "doable". Dunno if moons are available for that size though :(.

9mm out of snubbie wheelguns has a good rep for performance. And some very good load development in 9mm has happened of late - the Gold Dots work great of course but the Winchester 127gr Ranger-T and the Federal HST police-sales-only-but-you-CAN-get-'em monsters are amazing.
 
There is another obstacle to overcome....

The nominal groove diameter of the .357 is---well, 0.357 inch.
The groove diameter of the 9mm is .355--not to be confused with 9mm Makarov, which uses (I believe) a groove diameter of .366.
 
Thanks for the replies so far. As to why? pocket carry. I wear cargo shorts 95% of the time here in warm/humid Florida, and my waist line isn't going to allow me to add 2" for IWB. Since I have other 9mm, I was thinking it would be nice to use one of the lighter versions and have it converted. It's looking like a no-go so far, so back to the idea drawing board
 
Not a no-go just yet...

Have you considered the Taurus 605? Five rounds of 9mm Parabellum in moon clips would do the trick, I think.
 
For the money it would cost you to convert one, why not for for a pocket gun like the Ruger LCP? I know it isn't a 9mm, but with it's size, it really makes a perfect cargo / pocket gun.
 
The LCP is on the short list, as is the 642/442. As for Taurus, I haven't had good luck in the past - I would want to fire one first - but, you're right, it should at least merit consideration
 
9mm out of snubbie wheelguns has a good rep for performance. And some very good load development in 9mm has happened of late - the Gold Dots work great of course but the Winchester 127gr Ranger-T and the Federal HST police-sales-only-but-you-CAN-get-'em monsters are amazing.
Click to expand...
I've had that debate here on the forum. You can get near .357 magnum velocities in the 110-125 gr range with commonly available commercial loads for defense from a short barreled 9mm and with less flash and muzzle flip.
 
a) I have split the cylinder with a 9mm OAL and a 9mm load in a 38sp.

b) I have bent the frame of an Aluminum framed 38 sp with 2 gr more than a 357 mag load.

$700 down the toilet.

I could post pics of the bags of parts remaining, but you get the idea.
 
Well it can be done with a .357 J frame.
http://thefiringline.com/forums/show...&highlight=9mm
Click to expand...

That is my gun, it started out as a .38spl but if your read the text of that old post you'll see that the frame is the same as the M&P360 and, per S&W, there is no difference in the steel of the .357mags and .38spls, the chambers are just cut to different depths. I know guys that have converted aluminum framed guns with good success but personally I wouldn't do it. Since S&W doesn't chamber them for .357mag, I wouldn't try rechambering one to 9mm.

Since the 9mm conversion subject keeps coming up I'll give an update on it-

I've carried it almost everyday since that post, I have put 750+/- rds of standard 9mm 115gr FMJ through it, plus another 50rds of Federal 9BPLE 115gr JHP +P+, about 50rds of .38 Super, and 15rds of 9x23 Winchester. The gun has functioned perfectly with zero problems and shows no signs of stress or damage. It has proven to be functional and accurate, I qualified with it on our duty pistol course of fire (shooting from 3yds to 25yds) going through 100rds in about 35 minutes. My score was within a few points of what I shoot with my duty gun. The short cartridges and moonclips make reloads a snap.

The only issue I've had with it was that I would get rust on the edges of the cylinder flutes on really hot humid days when carrying in a pocket or ankle holster. I sent the cylinder to Robar and had them coat it with NP3 and haven't had any trouble since.

I've since learned that, like so many things, the conversion is a compromise as there is a minor loss of pressure thanks to the diameter of the chambers and the "freebore" travel in the cylinder.
On the plus side, I;ve found that the .357" bore vs .355" really doesn't mean anything in the real world, that .0002" just isn't the issue some folks seem to think it would be. The bullets engage the rifling and fly true, accuracy is good and there's no keyholing.

If you read that old post you know what I have into the gun, plus the cost of refinishing the cylinder, and it has been money well spent. The gun turned out exactly how I wanted it, it's performance has exceeded my expectations, and 2 1/2 years later I'm still happy with it. It may not be everyone's cup of tea due to cost, caliber, type of work done, or whatever, but it's works great for me.

SDC10427.JPG
 
I have three Airweight 637-2 J-frames that each have extra titanium cylinders chambered for .357 Mag and 9mm.
My preference for carry is 147gr JHP 9mm.
 
I’d rather pocket carry a pm9, or even a pm45. A 9mm 5 shot wheelie doesn’t make much sense for me.
 
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