Convert SP101 38 to 357

F350Lawman

New member
I have a 38 special SP101(really a SPNY -no hammer spur, DA only, heavy NYPD trigger) that I would like to convert to a 357.

I have been told that the gun I was issued is identical frame wise to the general public 357 minus the 38 special cylinder. I guess I could order another cylinder or have this one reamed to accept the 357 cartridge.

Anyone done or heard of this. I have 2 other 38specials so I figured why not. Probably a better idea to just change out the cylinder if possible.

Gun looks like it could handle mortar rounds :) the way it's built.
 
As best I recall, the first generation SP was .38 Special, and the second generation was chambered to .357 with no other changes and marked for 125 grain bullets only. This because the cylinder was not lengthened, just chambered for magnums. The later guns had slightly longer cylinders to take up to maximum standard magnum rounds.

Ayoob's shop, Tarnhelm Supply Co
http://www.tarnhelm.com/
will rechamber the .38 SPs to .357 for $65.
Their catalog says:
"Re-chamber to .357M Check cylinder for faults, stress cracks, and bore out to accept .357M. (On an old-style Ruger SP101, we recommend Federal brand 125/.357M only. Other ammo may be too long!) $65.00"
 
JimWatson

As best I recall, the first generation SP was .38 Special, and the second generation was chambered to .357 with no other changes and marked for 125 grain bullets only.


You are right! I now remember seeing the ad on the back of some gun magazine "Pocket Rocket" I think it was billed as w/ the 125g only thing mentioned. Ad was out about 1991 and had a picture of a guy in jeans suggesting it was the ultimate pocket 357.

I might try your suggestion or just order an extra cylinder.

Thanks
 
I think I would check with Ruger on the "no other changes". Quite often .38 and .357 guns that appear identical have a different heat treatment, or even a different alloy, for the cylinder and frame of the .357.

Jim
 
Ayoob claims that he showed Bill Sr.

an early SP that was modified by reaming. That's what convinced him to greenlight the magnum chambering from the factory.
 
F350Lawman

I remember an article in G&A when Ruger first introduced the first SP-101 in .357Mag. In this article they said that Ruger came out with the SP-101 in .357Mag becouse gun smith's were already reaming the.38spl cylinders out for the .357Mag. I remember them also saying that they would not suggest doing this.
In my opinion, by the time you get done reaming the cylinders or buying a .357 cylinder you probably would spend close to what a new SP-101 .357Mag would cost. Just a thought.
 
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