View Full Version : .357 to 9mm

March 28, 2008, 04:37 AM
I know Ruger used to make a SA conv revolver for both .357 and 9mm. What can be done to other guns in .357 to switch it to 9mm? Can you bore the cylinder out and then use a press in sleeve like they do with engine blocks to change the size? Or can blank cylinders be had to swap out the .357 for one drilled for 9mm?

Are you asking why bother when you can still find revolvers in 9mm? I don't want the Ruger, but having a Taurus 8 shot in 9mm with say a 4" barrel would take me longer to blow thru a hundred rounds than it does now with a glock 17L.

Besides I'm not a big auto fan anyways:D

James K
March 28, 2008, 04:26 PM
The main problem in using a rimless case like the 9mm in a revolver is extraction. Obviously, that is no problem in a SA type revolver which uses an ejector rod, but it is a problem with DA revolvers that have an extractor built into the rear of the cylinder.

It is possible to have a revolver cylinder cut for the use of "moon clips", and that can be done for 9mm to provide a means of extraction. There have also been DA revolvers made for the 9mm using "trick" extractors, but they were not generally successful. (The main reason for them was to allow police in some countries who were restricted to revolvers to use 9mm ammunition supplied by the military.)

In most cases the revolver cylinder is made specifically for the 9mm and moon clips or not, the 9mm still is supported on the case mouth. It would be possible to rig a system where 9mm and .357 would be fired from the same cylinder, but the result would be problematical with unwanted case bulging and dubious accuracy.

The barrel inside diameter would be a problem though a minor one for practical purposes. The .354" diameter 9mm bullet would expand to the .357" bore diameter of the .357 Magnum barrel, but accuracy would suffer. The reverse, would raise pressure slightly but also affect accuracy.


March 28, 2008, 04:39 PM

April 26, 2008, 08:29 AM
Ruger either does or did make a 9mm version of the DA SP101, I believe. The real problem I see with rechambering from a .357 to 9mm is that the 9mm headspaces on the case mouth and the .357 chamber is too long. You could do a .38 Special to 9mm Win Mag since the chambers are the same length, but not a .357 to 9mm.

Jim Watson
April 26, 2008, 08:33 AM
There are gunsmiths who will cheerfully take your money to ream a .38 or .357 cylinder for the tapered 9mm case and mill the rear of the cylinder for full moon clips to hold headspace and extract. Accuracy with the long jump to the barrel and the slight mismatch in bullet - barrel diameters is not covered in their advertising, for some reason.

I have not seen anybody offer to do it for an 8 shot Taurus, tooling up for the odd clip would be the limiting factor.