Model 48 accuracy with 22 mag and 22 LR cylinders?

nevada duke · Dec 24, 2015

Do any of you have experience with a Model 48 with both cylinders? Looking at one on an auction site, 8&3/8 barrel with aux. 22LR cylinder. Any velocity or accuracy reports or just remembered experiences are welcome. Thanks.

Best regards, Nevada duke.

Big Cholla · Dec 24, 2015

Many years ago I acquired a M 48 with a 4" barrel. I shot it extensively with all sorts of 22 Mag ammo. I was pleased with the performance but disappointed with the obtainable accuracy. I then got the bug to get a 22 LR cylinder for the M 48. I did so and fitted a new 22 LR cylinder. I again shot the resulting 22 LR "K" frame extensively with many brands and types of 22 LR ammo. I was taken back at just how badly some of them shot. The best still shot worse than the less than stellar 22 Mag. I did some research and found that S&W uses a barrel bore diameter of 0.222" for the 22 LR and 0.224" for the 22 Mag. At least the same twist rate was used for both. The larger size of the M 48's barrel was causing the 22 LR bullet to skid and mar up before grabbing and going out the barrel. I fitted a new 22 LR cylinder to two other people's M 48 during this time of experimentation. They didn't get any better 22 LR accuracy out of their M 48's than I did.

A few years ago I purchased my first M 617. And thought about fitting another 22 LR cylinder to it and then reaming out that newly fitted cylinder to 22 Mag. I did so on the 6" barrel. The resulting accuracy shooting 22 Mag thru a 22 LR bore barrel was amazing. I next did the same conversion on a M 617 with a 4" barrel. The 22 Mag accuracy was as good as the already excellent 22 LR accuracy but no better. All in all, I was pretty happy. I then did two more cylinder conversions to M 617s for friends. Both exhibited superb accuracy for the 22 Mag thru the 22 LR bored barrel. I have done both 6 shot and 10 cylinder conversions on the M 617. Obviously only 6 shot conversion on the M 48.

So, IMHO, putting 22 LR cartridges thru a 22 Mag barrel is probably going to be disappointing in accuracy. There will be a few of this conversion that will have good accuracy. Most likely because of "Tolerance Stacking" in an positive fashion between the ammo of choice and the M 48 barrel bore. It happens once in a great while.

Hope this helps some. ..........................

H Richard · Dec 24, 2015

That would be just as I supposed. I'm intrigued with your 617 to 22 mag conversions. Where did you find the supply of 22LR cylinders?

epj · Dec 24, 2015

In the mid '60's, my first handgun was a Ruger single six convertible. They supposedly addressed this problem with a .223 barrel. It was decently accurate with both cylinders.

Art Doc · Dec 24, 2015

I had a 48=3 with an extra cylinder and it was horribly inaccurate with the 22LR.

4barrel · Dec 24, 2015

Mine shot good with the correct cylinder. A long rifle in a mag cylinder is all over the place. This one was ordered with both cylinders.

SuperMan · Dec 24, 2015

I have had two 6", one 8 3/8" and still have a 4" Model 48s with the extra cylinder...all shot just fine with the .22 LR cylinder as long as quality ammo was used.

Currently I have the above 4" dual cylinder 48, a 17 with a 48 cylinder, an 18 with a 48 cylinder and a 35 with a 51 cylinder...all of these shoot great also but can't say they do significantly better than the 48s I have had.

The long barrel 48 of course shot like a rifle at long range... I have chronoed several brands of ammo but will have to see if I still have the data.

Bob

Big Cholla · Dec 24, 2015

Source?

H Richard said:
That would be just as I supposed. I'm intrigued with your 617 to 22 mag conversions. Where did you find the supply of 22LR cylinders?

1 used from each of ebay, Numrich & LGS

2 new from Brownells
.........................................BC

nevada duke · Dec 25, 2015

model 48 accuracy

Thanks to all who replied. BC and SP, you have saved me from an expensive adventure, so thank you. BC, your work with the K22 22LR sounds good. Did you observe any undue pressure signs with the .224 mags going down the .222 barrels? Fitting a magnum cylinder to one of our S&W 22s sounds like a much better idea at this point.

I did have a Ruger Single Six convertible at one time. I got indifferent accuracy from both cylinders. It went down the road pretty quickly.

Thanks to all and Merry Christmas from Nevada duke.

steelslaver · Dec 25, 2015

While the might be a small momentary pressure spike as the 224 bullet swedges down a..increase in volume has already occurred in chamber because bullet has moved forward the K frame guns which are robust enough for 357 mags, wouldn't even notice it.

SuperMan · Dec 25, 2015

From what I have read, the typical .22 LR bore is .2225, only .0015 smaller than the .22 Magnum at .224. USFA and Freedom arms only use the .22 LR bore for all their rimfires and they are much more accurate than Rugers or S&Ws.

Have had at least five Rugers with extra cylinders and all but one, a Single-Six Hunter, shot poorly with the LR cylinder. And the only Single-Six that I have shot with LRs that was accurate was a 70s vintage * marked stainless gun that from what I understand was bored for .22 LR instead of Magnum. All the Rugers shot great with Magnum ammo.

I also have a Model 53 with the extra Rimfire cylinder that is a great shooter with Jet or LRs. But it is also bored .2225 and can use bullets no bigger than .223 for reloading the .22 Jet ammo.

Bob

silentflyer · Dec 30, 2015

A buddy has a .22 mag/LR Ruger Single Six, 10" barrel, it's the only dual cylinder revolver I ever saw that was accurate with both. Tried to buy it more than once, he won't sell it,can't blame him. But I still give him a hard time about it.

Model 48 accuracy with 22 mag and 22 LR cylinders?

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