K22 conversions to 22 WMR

[Mister Heavyhand]

Have you measured the cylinder to determine it is longer than a normal K-22 cylinder?

22 Magnum fits in a rechambered 22LR cylinder. I have a dual cylinder 2" Model 34

Here is what I measured today. Both revolvers have 6" barrels and very similar stocks. A comparison between my K22 K153xxx (1952) and the K290xxx (1957) K22 22wmr conversion:
K153xxx K290xxx
Cylinder length 1.62" 1.62"
Barrel OD at muzzle 0.558" 0.590"
Overall weight 2 lbs 5 1/2 oz 2 lbs 7 1/4 oz

The SN on K290xxx matches on the butt and the ejector star. No number on the barrel or cylinder.

I will shoot it tomorrow and post more info.

Thanks,
Millard

 

[Retired W4]

I once bought a very nice mid-1950's vintage K-22 Masterpiece at a gun show. The barrel and all six chambers appeared dirty but I didn't bother to run a brush and patch down them figuring a lot of people think .22's don't need to be cleaned.

When I got it home and cleaned it I found the barrel and every chamber were severely corroded. Maybe some previous owner fired some old .22 ammo from prior to when it was non corrosive and let it sit ? Anyway, I had done quite a bit of business previously with the seller and he was a standup guy and refunded my money. I often wondered what happened to it.

It was a candidate for rechambering for .22 WMR for sure. Cosmetically it was excellent.

The same thing happened to me with a 22/32 HFT. I scrubbed the chambers until I was worn out. Loads fine but ejection, not so much. Bore is corroded but it shoots just OK. I posted the gun earlier. It lays on the table now, next to my laptop waiting for final disposition. I'll have to measure cylinder length for possible 22 mag conversion but I have to wonder if the gun is up to the extra pressure.

Check that. 1.25 non-counter bored cylinder. Looks like a no-go for 22 mag. Oh well.

 

[steelslaver]

I think I have an I frame 22lr cylinder
Another thought is running a 22lr reamer through the chambers of the cylinder you already have
May clean them up enough to eject better

 

[cruiserdan]

I have 2 Model 48's with the auxiliary 22lr cylinders, 1 from around 1959 for sure, not sure about the date on the other.

I love to hear more about the early gun.

Another story I heard (who knows if it's real) is that around the same time dual cylinders were offered you could send your 48 into S&W and have them fit a 22LR cylinder for you. For a fee of course.

I wonder if there is any way to confirm or dispel the story.

 

[2152hq]

\

Go actually measure some unfired 22lr bullets. I have and have yet to find any that are actually .222, they are all .223 or .224 Plus, although the groove dia of a 22 mag barrel MIGHT be .224 the land dia is usually closer to .218. While you may not get target rifle accuracy, very few people can shoot a 6" revolver well enough to tell any difference.

Add to this that the original 22WRF ammo was bullet dia .228
It was loaded w/ lead bullets only.

A lot of it gets shot in .22WMRF guns which are the smaller .224 bore. But the lead bullet 22WRF has no problem downsizing.

Through a tighter bore .22LR bbl it might increase pressures a bit but not enough to bother in a well built modern firearm.

A couple yrs ago SAAMI changed the spec for the bullet dia on the 22WRF from .228d to .226d.
I believe that was in regards to the use of the cartridge in .224 groove bbls (and sometimes a bit smaller).
Plus I think some of the newly loaded 22WRF ammo that comes out now and again is loaded with a jacketed bullet instead of the very soft lead bullet of the orig load.
Though it's likely a very thin jacket at that for easy passage down a slightly smaller bore.

Gotta keep the Lawyers quiet..everything seems to work out fine and no one is complaining of guns blowing up.

 

[Retired W4]

This is a little off subject but when Ruger started offering the convertible Single Six they opened up the bore slightly to accommodate the 22 mag. Not sure what it did to the accuracy when using 22LR in those. My old (late 50s) SS does just fine, with LR that is.

 

[steelslaver]

PO Ackley proved that if the chamber neck is large enough so as not to pinch the neck onto the oversized bullet, there will be no pressure increase, due to powder pressure maximum which is produced some distance down the bore, dependent on the powder used. The average would run 8" to 12".
In his test, he bored the chamber neck so a .30/06 case could hold and discharge a .358", 150gr. bullet without pinching. He used a standard 150gr. load of 4895 & there was no pressure increase over the same case loaded with a .308" 150gr. in the original chamber. In the article, 1st or second edition of his book, he noted that during the was (WW11) |The Germans experimented with a rifle barrel that was .323" groove to groove at the breech, but tightened to .257" at the muzzle and attained "wonderful velocity/pressure ratios. This prompted this experiment.

His books are very interesting reading. He had way more resources, curiosity and guts than most people will ever have