How are 38/357 revolvers converted to 9mm/38 Super

[earlthegoat2]

I was wondering what the maching processes were for this conversion and whether or not you can still shoot 38s in it.

Yeah, lazy Sunday curiosities..

 

[Starter52]

I would think a new cylinder would be needed.

 

[earlthegoat2]

The 9mm cartridge is wider than the 38/357 right?

Reaming it might be an option as opposed to cylinder replacement. Is there any other mechanical changes that must take place?

Also, is it advisable to start with a 357 magnum revolver if you were planning on shooting 38 Super or 9x23?

 

[WC145]

The cylinder is rebored to 9x23 and the cylinder face cut for moonclips. You can fire .38's or .357's through them but because of the larger chambers they fire form and stick, also hotter loads split the cases.

I have a S&W 360J that I had converted by Mark Hartshorne of Pinnacle High Performance www.pinnacle-guns.com. It is my BUG and off duty gun, I usually load it with 9mm but but it shoots great with .38 Super and 9x23 Winchester as well.

 

[rcmodel]

Chambers are reamed and cylinder modified to use moon clips.

Rimless rounds like the 9mm, 38 Super & 9x23 will not eject from a revolver without moon clips.

As for the desireability of doing the conversion?
Seems like a really bad idea to me.

The .355" bullet out of the much shorter case would be rattling down the .380" diameter .38/.357 chamber for quite a ways before it got to the .357" chamber throats.

Gas blow-by would result in power loss, and tipping bullets hitting the forcing cone crooked would give poor accuracy it seems to me.

You would also get bulged brass when shooting .38/.357 again in the oversize 9mm chamber.

rc

 

[padd54]

My old Ruger came with an extra cylinder for 9mm.

 

[WC145]

I've experienced no appreciable difference in accuracy from my gun's original set up. I don't know how much difference it might have made but I had the forcing cone chamfered when I had the work done because of some machining burrs.

There is some loss of velocity due to blow-by but there is still a substantial increase in performance over the .38spl and I don't feel any real increase in recoil over +P .38's.

 

[stiab]

If you have a modern S&W .357 revolver (or .38 Special for that matter), no modifications are necessary for you to shoot 38 Super. However, only Winchester and Magtech factory ammo will chamber, the others do not. Many people who have never tried it say it cannot be done, thinking that the 38 Super is not a straight case (it is), and thinking that the 38 Super does not have a rim (it does). No moon clips required. I am not recommending anyone do this, but I have done it in my S&W M28 and it works fine. These two brands of ammo will also chamber in Colt Pythons, and most modern (last 25 years or so) J frames and K frames in .38 Special. Again, I am not recommending it, just telling you what will work. The above does not hold true for the 9mm.

 

[Jim Watson]

There was a thread here recently where a guy compared a .38 Special rechambered to the 9mm - .38 Super - 9x23 combo to dedicated guns. The conversion gave lower velocity in all cases but a 115 grain 9mm still had higher velocity than a 110 grain .38 Special in an uncut gun.

 

[kdstrick]

Hey Jim, do you have a link to that thread? It sounds interesting.

 

[WC145]

Hey Jim, do you have a link to that thread? It sounds interesting.

I posted that thread, here's the link - http://www.thehighroad.org/showthread.php?t=467159 - The .38's were what I expected from the 637, the 9mm's were much faster than I expected from the Taurus 905, and my converted gun fell somewhere in between. I need to order up some of the hot CorBon .38 Supers and see what they do.

 

[Jim K]

Whether .38 Super/.38 ACP will chamber and fire in an unaltered .38 Special/.357 Magnum revolver is a matter of tolerances. With some of my revolvers, it slips right in; with others it can't be forced in. When it does chamber, the semi-rim allows it to headspace and fire with no problem.

Jim

 

[1911Tuner]

LIke Jim said...Some will do it. Lowered pressures and velocities due to the longer jump into the chamber throat. Don't expect .38 Super performance. I chronographed a lot of Winchester 125 Silvertips through a 5-inch autopistol barrel, and then through a 4-inch Python. There was a full 100+ fps difference. The barrel/cylinder gap accounted for a little of it...but not that much.

 

[stiab]

Whether .38 Super/.38 ACP will chamber and fire in an unaltered .38 Special/.357 Magnum revolver is a matter of tolerances.

For modern revolvers, I really believe it is a matter of the ammo, not the gun's chamber. Winchester ST and 130 FMJ and Magtech 130 will fit in ALL my modern revolvers, that's about a dozen Colt and S&W. However, in these same revolvers ammo from Armscor, PMC, UMC, Remington, Aquila, Federal, Fioochi, and Corbon will not fit. Older guns, like a 1970 Model 60 and a 1968 Detective Special will not allow any ammo inside, regardless of who it is made by.

 

[tunnug]

Just a reminder to keep an eye on friends when shooting your guns and ties in to this thread.

We went out shooting several guns that I have and I explained the ammo to my sons friend, experienced shooter but young and not familiar .38 super.

I'm standing there when he steps up to shoot my 686 and proceeds to start firing, the gun sounds weak with no recoil to speak of, so I stop him and ask about the ammo, he hands me the gun and when I opened it I find that he had loaded the .38 super.

He had taken 3 shots and they had impacted the steel gong but it had sounded like someone was hitting it with rocks, they managed to work because of the small rim but had lost a lot of power.

 

[earlthegoat2]

they managed to work because of the small rim but had lost a lot of power.

Did they lose lots of power compared to 38 special or 357 magnum or both? Or just compared to 38 Super autos?