Boring a 22 LR cylinder into a 22 WMR

[Tokarev]

If the cylinder length is sufficient, is such boring/reaming possible? I can't think of the reasons it should not be. Ideas?

[Winger Ed.]

The only thing that comes to mind is a possible issue with the wall strength of the cylinder from the .22Mag's higher pressure.

Revolvers that offer both cylinders probably have a frame that is a little more 'beefy' to handle the Mag pressures.
One that was only ever intended to shoot LR---- maybe not so much.

It goes along with my thinking that if you want a .357Mag,,,,, buy one.
Don't try to make your own out of a .38Spec.

[deltaenterprizes]

The only thing that comes to mind is a possible issue with the wall strength of the cylinder from the .22Mag's higher pressure.

Revolvers that offer both cylinders probably have a frame that is a little more 'beefy' to handle the Mag pressures.
One that was only ever intended to shoot LR---- maybe not so much.

It goes along with my thinking that if you want a .357Mag,,,,, buy one.
Don't try to make your own out of a .38Spec.
Good advice!

[LAGS]

Aren't the bores on a 22 mag just a little larger diameter too ?

[45DUDE]

I had a model 48-4 in the 70's with factory cylinders for both. It was ordered locally. It shot both mag and lr ok. I never measured my barrel. I got broke and sold it. If you bore the cylinders it will not group lr any more. The head on a mag case is larger also. I had a Remington 510 clunker I bored to a mag but I had to bevel the front of the throat a little. My 48-4 had the complete extra cylinder with rod. Cylinder metal on a Smith is harder than a woodpeckers lips. I would farm it out.

[Tokarev]

I already have a gun that takes both cylinders, and the 22LR cylinder for it. The idea is to buy another 22LR cylinder for it, and to bore it because 22WMR cylinders for it are made of Unobtainium 264.

So if I bought a set of reamers from .2264 that the 22LR chambers currently are and up to .2440 that WMR should be, in what increment should I buy them, to be able to ream chambers concentric with the throats? Or am I oversimplifying the process? Do I have to drill the chamber in the same diameter, to WMR length first? Until now, I only ever used a chambering reamer, so I've no idea. I'd like to avoid buying a reamer or going through the hassle of renting one, but I can do with a bunch new chucking reamers as I need them all the time.

[NSB]

I’m pretty sure the chamber pressure for .22lr and .22wmr are the same. IIRC, it’s 24,000 for both.

[Martin Luber]

I don't know what Ruger does regarding bore for their convertibles but the mag is bigger in bullet diameter . I would think they design for 22LR and the mag bullet is compromised. It won't work going the other way. I wouldn't rework an existing cylinder but I would get a spare preferably in the mag caliber already.

[M-Tecs]

I don't know what Ruger does regarding bore for their convertibles but the mag is bigger in bullet diameter . I would think they design for 22LR and the mag bullet is compromised. It won't work going the other way. I wouldn't rework an existing cylinder but I would get a spare preferably in the mag caliber already.


22LR bores are .222". 22 Win mag bores are 224". When Ruger started doing the convertibles they used 224" on them but they left the non-convertibles at .222". Not sure if that is still true today but you do lose some accuracy with 22LR in a .224 bore.

[Tokarev]

This is not really the right thread for comparisons or and merits of each caliber.

[cwtebay]

What M-tech said. If you've owned a convertible you know that it shoots either LR or Mag well. Not both.
Boring out a cylinder shouldn't hurt much other than the accuracy of the revolver.

Sent from my Pixel 5 using Tapatalk

[NSB]

What M-tech said. If you've owned a convertible you know that it shoots either LR or Mag well. Not both.
Boring out a cylinder shouldn't hurt much other than the accuracy of the revolver.

Sent from my Pixel 5 using Tapatalk
I can’t agree with that statement. I had a convertible and it shot both very, very well. I shot a 77x80 with the .22lr at the 1990 IHMSA Internationals with that gun and it would shoot .22wmr around 1” groups at 50 yds. The bore diameters on those guns are not different contrary to all you hear saying they are.

[M-Tecs]

The bore diameters on those guns are not different contrary to all you hear saying they are.

https://saami.org/wp-content/uploads/2019/06/ANSI-SAAMI-Z299.1-Rimfire-2015-R2018-Approved-2018-06-13.pdf

Page 14 & 15 for 22lR match and standard bore/groove sizes. Page 18 for 22 Win Mag bore/groove size.

Claim is currently Ruger is using .224" on all their single six's convertible's and non-convertible's. A buddy has a 1961 windage adjust only rear sight single six that shoots very well. I personally measure it and it is 222". I have been trying to talk him out of it for 20 plus years.

Dad had a very early super single six 22 LR only that shot very well. He purchased in new 1965. When I was about 14 he traded it for a convertible. That was a mistake. It shot 22 mag shot very well. Not so much with the 22 LR. Since than I have owned and sold 3 additional single six's. I guess I just was unlucky with the three of them since they all were just mediocre accurate with the 22 LR. I currently own zero single six's.

[longbow]

You might want to look at the SAAMI specs here:

https://saami.org/technical-information/cartridge-chamber-drawings/

which show .22 LR bore as 0.217" and groove as 0.222" and .22 Mag. bore as 0.219" and groove as 0.224".

.22 Mag. also operates at slightly higher pressure though maybe not enough to be an issue.

Having said that I have a 1980's vintage Ruger Single Six that is very accurate with .22 LR and .22 Mag. both. Not sure which bore and groove diameters it has but it works!

Longbow

[Walks]

I have a Colt Peacemaker .22 with both cylinders. It groups from both cylinders into an 1 1/2" at 25yds.
My NM Super Single Six will do even better than that from a rest.

However I have My Dad's OM Single Six in .22Mag only. it shoots better then I can hold. I had a .22LR cylinder fitted to it.
The .22LR shoots like a shotgun with a cyl. bore choke. A 25yd group I can barely cover with my hand. I have BIG hands.

There are plenty of choices in .22mag, why rebore a cylinder ? Why not just buy another revolver ? Easier and safer. Unless you just want to do it.

[indian joe]

Aren't the bores on a 22 mag just a little larger diameter too ?

I have a twin cylinder ruger sinlge six - yes the bore is bigger to accomodate the magnum bullet . Due to ammo cost I rarely shoot magnums in it. Its never been particularly accurate with 22LR - not orrible but nothing to write home about, I have two cap and ball revolvers I can shoot a better target with most anytime I try. I have seriously thought about rebarreling it with correct 22 tube and losing the magnum cylinder.

[Tokarev]

Yes, I totally understand that everyone has their own opinions on the merits of 22LR and 22WMR and on the differences about them but this thread has been created solely for the purpose of seeking advise on the process of boring out the chambers. I have to ask moderators to step in and delete the offtopic posts. This is a gunsmithing subforum. Your posts belong in Rimfire, so pleas open your own threads and discuss that there.

[DougGuy]

There is also the Osammy EO of 2016 making conversions like this from simple gunsmithing into manufacturing. They impose a $2,200.00 annual "fee" for any shop or smith that does work such as accurizing, caliber conversions, extended magazines, it's a stupid list that if you are in violation of they can fine you and can do it retroactively.

[Tokarev]

There is also the Osammy EO of 2016

What are you talking about?

[contender1]

"22LR bores are .222". 22 Win mag bores are 224". When Ruger started doing the convertibles they used 224" on them but they left the non-convertibles at .222". Not sure if that is still true today but you do lose some accuracy with 22LR in a .224 bore."

This statement is kinda true.

A little more history.
Ruger Single-Six collectors acknowledge that when Ruger started building the Single-Six,, it had a bore diameter of .222. When the .22 mags were introduced,, they had a bore diameter of .224. These guns were marked ".22 Magnum" on the frame.
Then they offered the .22 mags with a spare .22 LR cylinder,, to be used in guns with the .224 bore. Finally, they dropped the .22 mag only guns,, changed all the barrel bores to .224. Practice continues to this day.
Generally,, the collectors use the serial numbers of the Single-Six models as follows;
1-150000 is a .222 bore,, while any built with serial number 150001 & up is a .224 diameter.

But back to the OP's question.
Many gunsmiths have bored out .22 LR cylinders to accept the .22 Mag ammo. It depends upon the gun as to how much pressure it can accept. In general,, most quality names are fine with it.
If you are unsure as to the bore diameter,, slug the bore.

[M-Tecs]

Yes, I totally understand that everyone has their own opinions on the merits of 22LR and 22WMR and on the differences about them but this thread has been created solely for the purpose of seeking advise on the process of boring out the chambers. I have to ask moderators to step in and delete the offtopic posts.[ This is a gunsmithing subforum. Your posts belong in Rimfire, so pleas open your own threads and discuss that there.

Understanding that each cartridge has a different bore size is 100% germane to the "gunsmithing" question if it is viable to rechambering.


If the cylinder length is sufficient, is such boring/reaming possible? I can't think of the reasons it should not be. Ideas?

Yes, the bore sizes are different with potential issues if it was a .222"


I already have a gun that takes both cylinders, and the 22LR cylinder for it. The idea is to buy another 22LR cylinder for it, and to bore it because 22WMR cylinders for it are made of Unobtainium 264.

So if I bought a set of reamers from .2264 that the 22LR chambers currently are and up to .2440 that WMR should be, in what increment should I buy them, to be able to ream chambers concentric with the throats? Or am I oversimplifying the process? Do I have to drill the chamber in the same diameter, to WMR length first? Until now, I only ever used a chambering reamer, so I've no idea. I'd like to avoid buying a reamer or going through the hassle of renting one, but I can do with a bunch new chucking reamers as I need them all the time.

I did miss this one and that does address that in this case the bore size should not be an issue. Had you posted that in the first thread you would not be having your current hissy fit. As to not being available eBay currently has several 22 Mag cylinders with a buy it now price of $175 to $185.

As to using a chucking reamer to do the job that depends on what you have for machining capabilities and machining abilities? Using the term boring verse reaming indicates abilities are limited. With a milling machine like a Bridgeport it is very doable to hold concentricity with the 22LR chamber using chucking reamers. Out of a standard drill press I don't have a clue if you can do without affecting accuracy but personally using chucking would be a method of last resort. If you're just looking for it to go bang that's a different story. Babba specials are easy. Professional level results not so much.

I did provide you will SAAMI chamber spec's and had you looked at them you would see that the rim, headspace sizes and cylinder throats are different also. If the cylinder is recessed that has to be addressed. The headspace is also different and that again will not be dealt with using a standard chucking reamer. There with be a difference between the chamfer angle of a chucking reaming and the SAAMI chamber also.

With the equipment and abilities I have I could match a SAAMI chamber using chucking reamers with a modified chamfer angle and addressing the rim and headspace issue is a second op. Again, if I was doing this conversion using chucking reamers would a last resort method. Using the proper chamber reamer or purchasing a used cylinder is a much better option for someone with limited machining abilities and equipment.

What you have for equipment and abilities I don't have a clue. I would suggest that you start by reviewing the SAAMI chamber specs to understand all of the differences between the two cartridges. Hint - in addition to the body diameter you also have different rim, headspace and cylinder and throat sizes.

Rechambering a cylinder to a different caliber is done all the time so that part is not an issue. The question is do you have the equipment and abilities to do a professional level job or a bubba special?

[pietro]

.

It can be done, if the cylinder length is OK - there's plenty of .22LR Ruger Bearcats out there with cylinders rechambered to .22 Mag (google).

.

[M-Tecs]

"22LR bores are .222". 22 Win mag bores are 224". When Ruger started doing the convertibles they used 224" on them but they left the non-convertibles at .222". Not sure if that is still true today but you do lose some accuracy with 22LR in a .224 bore."

This statement is kinda true.

A little more history.
Ruger Single-Six collectors acknowledge that when Ruger started building the Single-Six,, it had a bore diameter of .222. When the .22 mags were introduced,, they had a bore diameter of .224. These guns were marked ".22 Magnum" on the frame.
Then they offered the .22 mags with a spare .22 LR cylinder,, to be used in guns with the .224 bore. Finally, they dropped the .22 mag only guns,, changed all the barrel bores to .224. Practice continues to this day.
Generally,, the collectors use the serial numbers of the Single-Six models as follows;
1-150000 is a .222 bore,, while any built with serial number 150001 & up is a .224 diameter.

But back to the OP's question.
Many gunsmiths have bored out .22 LR cylinders to accept the .22 Mag ammo. It depends upon the gun as to how much pressure it can accept. In general,, most quality names are fine with it.
If you are unsure as to the bore diameter,, slug the bore.

Thanks, I did not know the change point. I will have to start looking for a 1 - 150,000 with a .222 bore.

[MostlyLeverGuns]

My 1970's 3 screw Ruger Super Single-Six is very accurate with both 22LR and 22 Mag. To rechamber a 22LR cylinder, a piloted 22 Mag reamer with a pilot that fits the CYLINDER bores is what you would need. It is the CYLINDER bores that need to be slugged, maybe the barrel throat might need some work so both cartridges work accurately

[Cap'n Morgan]

For what it's worth, I rechambered several 22 LR rifles to 22 WMR over the years. They were all single shot bolt rifles (and a couple of Savage 22/20 combos)
The max pressure in 22LR and 22WMR is apparently the same, but I found the 22WMR case would start to bulge if not properly supported (too large firing pin holes or extractor slits)

[M-Tecs]

For what it's worth, I rechambered several 22 LR rifles to 22 WMR over the years. They were all single shot bolt rifles (and a couple of Savage 22/20 combos)
The max pressure in 22LR and 22WMR is apparently the same, but I found the 22WMR case would start to bulge if not properly supported (too large firing pin holes or extractor slits)

Did they show the same pressure signs in the original 22LR chambering? If not, that does indicate that pushing a jacketed 224" bullet down a .222" barrel does increase pressure enough to possibly create issues?

I have never done a 22 Mag on a 222" barrel so this this is strictly secondhand info. I have read some people have had good success with this conversion and some have had issues like you described. Some have claimed sticky extraction or split cases also but both of those issues could be related to the quality of the chambering.

[Cap'n Morgan]

Did they show the same pressure signs in the original 22LR chambering? If not, that does indicate that pushing a jacketed 224" bullet down a .222" barrel does increase pressure enough to possibly create issues?

I have never done a 22 Mag on a 222" barrel so this this is strictly secondhand info. I have read some people have had good success with this conversion and some have had issues like you described. Some have claimed sticky extraction or split cases also but both of those issues could be related to the quality of the chambering.

There were no pressure signs before rechambering. I didn't add a "normal" throat to the barrels, just a 30 degree leade from the reamer, and you're probably right that the pressure were higher than it would've been in a .224 barrel. It was before I could afford a chronograph, otherwise it would have been interesting to see the muzzle velocity.

The difference in bore size should not pose a problem in a revolver as the cylinder throat will act as a free bore.

[M-Tecs]

There were no pressure signs before rechambering. I didn't add a "normal" throat to the barrels, just a 30 degree leade from the reamer, and you're probably right that the pressure were higher than it would've been in a .224 barrel. It was before I could afford a chronograph, otherwise it would have been interesting to see the muzzle velocity.

The difference in bore size should not pose a problem in a revolver as the cylinder throat will act as a free bore.

As I have stated I have never done this conversation, however, everything I have read on the subject has been based on .222" revolver conversations. I would think the cylinder gap would also vent enough pressure to make pressure a non-issue. However, some stilled claimed sticky extraction and/or split cases but was that a pressure issue or poor craftmanship on the rechamber?

If I ever find a 222" barreled Single Six I will fit one of my spare 22 mag cylinders. I have one blued and one Stainless. I have owned 3 different New Model single Six's. None shot well with the 22LR cylinder. Each of these was purchased used or taken on trade so maybe the reason they went down the road is the original owners had the same issue. I kept a couple of 22 Mag cylinders for future use. Orignially, I planned on re-barreling one with a 222" barrel but trade opportunities came around first and they went down the road. All as I really want is one that shoots the 22LR well. If I got lucky enough to find one in 224" barrel that shot well I would be just as happy but I have not been that lucky.

[indian joe]

Yes, I totally understand that everyone has their own opinions on the merits of 22LR and 22WMR and on the differences about them but this thread has been created solely for the purpose of seeking advise on the process of boring out the chambers. I have to ask moderators to step in and delete the offtopic posts. This is a gunsmithing subforum. Your posts belong in Rimfire, so pleas open your own threads and discuss that there.

well what got up your nose so quick? !!!!!