Your thoughts, .22 to .22mag

[Llance]

I see this as another opportunity to have a duel gun, one cartridge combination. I have a Marlin Model 57-M .22 magnum and this would give me that combination. I reason that adding a .22 magnum to my revolver collection is a desirable option. If I can do it cheaper with a mill and reamer or just a reamer it might be worth the expense. If I can do it with a new (used but good condition) cylinder reamed or one already chambered for .22 magnum then that's okay too.

Both of my K frame .22's are six inch models and I don't like the idea of spending fifteen hundred dollars, or more, just to have a .22 magnum revolver. And of coarse, I want it to be a S&W. I have no intention of using the conversion for target shooting so if it shoots to minute of rabbit, it's good enough for me, considering my 72 year old eyes aren't up to the task of bullseye shooting any more.

As far as the price of ammunition is concerned I have something close to 2,000 rounds so I am not going to worry about it anytime soon. BTW I bought the ammo over the years after I bought the Marlin back in, I think it was 1972. I'd just buy it when ever I saw a good price on it. One time I bought a brick of .22 magnum ammunition (new ammo) in a retail store for $14.99. Yes, that's right, less than fifteen dollars for a brick of twenty-two magnum ammo.

Mind you if I could find a poor to fair condition M-48 at a reasonable price I'd jump on it but all the ones I've seen are closer to $1500.00 and above which is far beyond the swell of my wallet. And I've been convinced by several people on this site (and I trust their judgement) that to have a used but less than perfect condition revolver is not a bad thing.

I have compared rim diameter of .22LR and .22Mag and I don't see enough difference to reason having to get a new extractor assembly, except it would make changing out the cylinders easier, which is why I'm asking for advice here.

 

[steelslaver]

Get a cylinder with a ejector star. For one thing the pin type stars will not often exchange as the pins must be perfect fit and I believe they are match drilled at factory. I know I have not had any luck at it. I have bought about 6 or so K22 cylinders for under $100 apiece, You can rent a reamer from 4D Reamer rental for $34 plus shipping. Some brake cleaner and good cutting oil, a padded vise, a tap handle plus time and effort and your good to go. I use a mill on very low speed myself, but you could do it by hand in a few hours.

 

[armorer951]

You can buy a brand new 648 cylinder from Numrich for under 80 dollars. A small amount of detail fitting, and cutting the new ratchets on the extractor provided with the new cylinder is all that is necessary.

 

[rbmac52]

I would never suggest to someone not to do such a conversion, as it is an individual choice. However, I would never consider buying a gun that has been modified in such a way. In my opinion, it detracts from value considerably. My suggestion would be to find a revolver chambered in the caliber you are considering.

 

[WR Moore]

Reading through this, I see some confusion between bore diameter (measured between rifling lands) and groove diameter (bottom of the rifling grooves). Possibly some don't realize there is a difference. I went and lost the reference I had that gave bore/groove/rifling twist specs for common cartridges for both Colt and S&W. Foggy and not always reliable memory is that .22 rf groove diameter is 0.222 in while the .22 WMR is 0.224 in.

 

[4barrel]

I had a 48 with both cylinders in the 70's. It shot plenty good but if you shot long rifle in the mag cylinder it was all over the place.

 

[smitholdtimer]

Just another conversion here........

My problem was that I was seeking a Model-648, I looked for more than a year and never saw one for sale, in person. I attended many gun shows but never saw a model 648 for sale. I was already in possession of a M-617-1 so I sought out a compatible Model-648 cylinder (ejector star is different during the dash 1 engineering change) so be mindful when ordering your magnum cylinder. Purchased a cylinder with extractor from Gun Parts Corp. and had it fitted & timed to the M-617. I actually shot it this passed Monday and continue to be satisfied with my decision to add the cylinder conversion since the M-648 was not available. I'm not advocating that anyone employ this method but mine sure works just fine. remember the sign at the diving board: ("Dive At Your Own Risk")

 

[Muley Gil]

I wanted a .22 Magnum cylinder for my stainless New Model Ruger Bearcat, but Ruger doesn't offer that option anymore. I bought a second stainless .22 LR cylinder and rented a .22 Magnum reamer from 4D. It took about an hour to do it by hand.

Hint: if you get a reamer from 4D, rent their handle as well. My tap handle didn't and I had to improvise.

 

[outta_ammo]

Reading through this, I see some confusion between bore diameter (measured between rifling lands) and groove diameter (bottom of the rifling grooves). Possibly some don't realize there is a difference. I went and lost the reference I had that gave bore/groove/rifling twist specs for common cartridges for both Colt and S&W. Foggy and not always reliable memory is that .22 rf groove diameter is 0.222 in while the .22 WMR is 0.224 in.

Nothing foggy about your memory. Those are the SAAMI specs, with bore diameter .005 less in each case.

 

[350mag]

Just like armorer951, I did his conversion to a Pre-18. Works like a champ. If you don't mind the semi/sorta pinto look. Cylinder with extractor from Gun Parts Corp for about $80 plus some other parts. Shoots really well.

Stu

Got my 648 cylinder from Numrich. The only part I need is a center pin with the shorter tail. Still looking.


Sent from my iPhone using Tapatalk

 

[LoboGunLeather]

Good post, plenty of solid advice from people who have experienced exactly what to expect.

The most compelling comments I have seen are those comparing the actual ballistic performance of .22WMR vs. .22LR in handguns. Velocities out of the shorter barrels are not significantly greater with the magnum ammo.

.22 WMR ammo is loaded to provide optimum performance in typical rifle-length barrels. I can see the utility of a .22 WMR revolver as a companion piece to a .22WMR rifle, offering interchangeable ammo for both, but I would not expect "magnum" level performance with the revolver.

The other concern I have is altering a perfectly good S&W revolver by rechambering the cylinder, thus reducing its value significantly.

My $0.02 worth.

 

[austintexas]

I have both 22 and 22 mag revolvers. I very rarely shoot 22 magnum. I do most of my pistol shooting at the range. Paper doesn't care who kills it. Except for the current madness, 22 long rifle is way cheaper to shoot and more available. I have a Stevens favorite I had converted in 1964, I bought the rifle with the usual crappy barrel, My gunsmith at Shooters Paradise had a used marlin 22 barrel. He chambered the barrel in 22 mag, modified the extractor, drilled and tapped the barrel for scopemounts. It shoots just fine with the 22 barrel. I've killed a lot of pests with it. Reason I did this was I had seen other Stevens done by him and there were not a lot of rifles around that were chambered for 22 mag at the time. Besides that it was cheap. I paid $3.50 for the Stevens. $10 for the conversion (parts and labor). If you think the cost was bogus you have to stop and remember I was working for Fisher Electronics for $1.27 and hour. It was 1964 you know. I wouldn't modify a nice M-17, go the extra cylinder route, the revolver will be worth more If you decide to sell it with 2 cylinders.
SWCA 892

 

[AJ]

Read here for bore diameter:

.22 Winchester Magnum Rimfire - Wikipedia

.22 Long Rifle - Wikipedia