You would first need to find out if that old of a rifle was built to withstand a .22mag. recoil. I know some older Marlin 39's are not for use with HV rounds. Just something to check into before altering the chamber. As far as altering a .22lr chamber to a Magnum, you can do it. If you have a recessed bolt face, you cannot. The magnum rim is slightly larger in diameter than the .22lr rim. Also, after altering you cannot shoot .22lr rounds in this rifle again. The magnum case has the larger rim as stated and the case tapers slightly from rim to case mouth. Meaning the chamber will not be suited for the long rifle rounds.

 

Magnum in a long rifle

My guess is that I believe the 22 mag has a higher pressure, recoil and bolt thrust and I believe the bore is larger in a 22 mag, thus you would have to over come pressure trying to squeeze the 22 mag down the 22 long rifle bore even though the difference is very small. And it looks like that rifle probably locks up on the bolt handle I wouldnt do it. But I may be wrong about this stuff though. STBE

 

I thought that the .22magnum has a different twist rate than the .22lr? Can any one comfirm this?

 

Savage makes all their .22LR and Magnums the same - 1:16 twist.

Ron

 

The bore is different as well as the chamber. The cartridges may both be referred to as .22, but they are entirely different.

 

Bore of .22 Magnum is .224. Bore of .22 LR is .223.
You have to rebore the barrel as well.

 

Come on now!! You are talking about 1000th of an inch with LEAD bullets. Not a problem............NOW, with certerfire ammo you might want to look again.

 

rechambered many to 22 mag...no bbl problem savage cub 33" long fits anywhere....accutrigger, safety on rt side ...FUN..redone savage stevens repro 71-72-74 pins are strong enuff, small groove on top of block to clear longer case...older 22s would pass on action & pin being safe

 

The average 22 mag barrel is a 1 in 14" twist, but shoots generally lighter and faster projectiles so a 1 in 16" should work fine for at least the light ones. I rechamber these all the time. .001" or .002" does not make enough pressure difference in rimfires to matter. Some of the most accurate 22 mags I have done are on regular.22lr rim-fire barrels. I probably would not do a rechamber on a .216" Benchmark or a tight bore Lilja. I still dont think it would be enough to generate enough pressure to rupture a case but I dont want a customer to find out.
I do refuse a lot of older bolt gun rechambers, simply because of there condition. The bolt face is usually sloppy enough in a lot of models to accomondate the larger rim.
A tight bore is desirable for accuracy, it tends to shoot a larger variety of bullets more accuratly. Some of my most accurate 22 Hornet and k-Hornet barrels are made with 22 mag barrels which are a thousandths or two smaller that the standard .224 bore.
I usually suggest to leave an older 22LR repeater alone Enjoy it for what it is / was and just buy a 22mag or a 22LR Single shot breakopen and rechamber that. The exception is the Ruger 77/22 they can be converted.

Here is the 1.060"G/M barrel specs.
.22LR .218/.223
.22Mag. .219/.224
.223 .220/.224

The G/M 1.20" 22LR is .218/.222

This is only one barrel makers specs. There are a a few different ones, everyone has there own recipe.
Once you get into High pressure cartridges barrel diameter becomes more critical.

 

The average 22 mag barrel is a 1 in 14" twist, but shoots generally lighter and faster projectiles so a 1 in 16" should work fine for at least the light ones. I rechamber these all the time. .001" or .002" does not make enough pressure difference in rimfires to matter. Some of the most accurate 22 mags I have done are on regular.22lr rim-fire barrels. I probably would not do a rechamber on a .216" Benchmark or a tight bore Lilja. I still dont think it would be enough to generate enough pressure to rupture a case but I dont want a customer to find out. I do refuse a lot of older bolt gun rechambers, simply because of there condition. The bolt face is usually sloppy enough in a lot of models to accomondate the larger rim. A tight bore is desirable for accuracy, it tends to shoot a larger variety of bullets more accuratly. Some of my most accurate 22 Hornet and k-Hornet barrels are made with 22 mag barrels which are a thousandths or two smaller that the standard .224 bore. I usually suggest to leave an older 22LR repeater alone Enjoy it for what it is / was and just buy a 22mag or a 22LR Single shot breakopen and rechamber that. The exception is the Ruger 77/22 they can be converted. Here is the 1.060"G/M barrel specs. .22LR .218/.223 .22Mag. .219/.224 .223 .220/.224 The G/M 1.20" 22LR is .218/.222 This is only one barrel makers specs. There are a a few different ones, everyone has there own recipe. Once you get into High pressure cartridges barrel diameter becomes more critical.

What about a 1915 Stevens “FAVORITE”? Could it be redone to shoot a .22 magnum or a .22 Hornet! With the rolling block I figure it would be easy! Just bore it out!! But would the block except the pressure

 

part 2....some barrel I.D. are different...have had to reduce 22 mag reamer pilot size to fit...also made a little jig to grind rim recess in bolt face..some need a little bigger & deeper as mag rims( not all the same) are thicker than 22lr(bolt must close with right pressure)...have to do this correctly as rim recess may not be a full circle so centering needs to be accurate to remain concentric with chamber & so extractor works....also as a preliminary test to see if conversion is doable so bolt opens far enuff or block drops enuff to clear longer bullet on entry & ejection

 

Ruger Single-six

The convertible revolvers use different cylinders with the same barrel bore, so I would expect that the difference in usual bore diameters would not be a problem. Seems like action strength and bolt face and barrel face modifications would be the major concerns.

 

Exactly. I get the picture here. There are a lot of nuts who know NOTHING about a .22 Magnum.

 

The convertables (.22LR/.22 Magnum) use .224 bores. They count on the .22LR lead bullet upsetting to fill the lands and grooves safely with accuracy.
No way can you shoot a .22 Magnum down a .223 (.22LR) rifle bore without pressure problems. No way.

 

Its been done many times with a .22lr bore without pressure problems. But... this is why, in my first post, I told him to be sure to check and see if that old of a rifle was made to withstand the pressure of a .22 magnum. There arev a few guys here who are actually smiths, or have worked for gunsmiths, as I have, and know this can be done, but the age of the firearm is the main factor of whether or not it will stand up to the magnum pressure.

 

Accident waiting to happen.

 

The WMR has a longer case with significantly higher pressure than any .22LR past or present. I think it's about twice the pressure. When the bullet engages the smaller bore (the .22 Magnum is a true Jacketed Centerfire .224 bullet like a .223, .22-250, .220 Swift, .222 Rem, etc) you significantly increase rear chamber flash pressure. Your gun could blow up.
Keep in mind many older .22 short single shot rifles of all makes have blown up because the years and use finally get to the older models.
I wouldn't even attempt a rechamber of any .22LR to a .22WMR. Chamber pressure is really high, actions (like the 39A Marlin and BL 22 Browning) CANNOT handle it, bores HAVE to be reamed at Centerfire .22 dimension: .224.

 

Max chamber pressure .22 LR = 7,500 psi
Max chamber pressure .22 Magnunm = 26, 000 psi
Nuff Said.

 

Like I said, your not a gunsmith unless you are and have not said. Take a look at the CZ .22's. They have a bore of about .219-.221. Much tighter than the .001 your worried about. Todays barrels can withstand twice the pressure you have listed as tooo much. Like I said again, its the age of the rifle that lets us know if the barrel was made back then to withstand the pressures of todays loads.

If you look at some high powered rifles, and the small diameters of some of their actions and barrels, and they can withstand pressures upwards of 60,000 PSI....??? Nuff Said.:bthumb:

 

One other thing I didn't see mentioned is the barrel steel. Even if you did the conversion and it didn't crack ,rupture or blow something I bet the steel is too soft for the jacketed 22 mag. I remember reading about old 22LR guns converted only to have the rifling wash out after a couple 100 rnds. I'd leave it as is and shoot Stingers or one of the hypervel rnds. Besides, a used 22 mag bolt gun isn't all that expensive if you want one. JMHO

 

Too much worrying going on here. Re chamber it and shoot it.

 

Metallurgy

A couple have mentioned the barrel steel and the rating of the action. My brother and I shot my mothers single shot Win made in the 1910-30's patents all were older from the 1800's to the oughts. My mother had always shot shorts in it. Of course we had to shoot HV LR and in time Mini Mags and Stingers one day my brother was shooting next to me and the bolt blew back into his thumb knuckle the howling commensed. We looked found the bolt handle. This rifle locked and head spaced on the bolt handle. My bet its age and the constant use of hot stuff caused the bolt to break loose from its attaching hole. We had a gunsmith silver solder it back in and shot only shorts afterward. Anyway if not rated for Win Mag I bet you could have a bolt in your face or gall and lose the headspace creating a problem. STBE

 

I'd recommend you look up SAAMI and read "Unsafe Cartridge Combinations."

 

http://www.saami.org/Unsafe_Combinations.cfm
There are reasons we don't make certain conversions and I suppose the legal and written stuff is more convincing than a proclaimed reamer of gun barrels and chambers.

 

rechamber

does anyone, i don't, think that any mass produced rifles today can keep
the chamber or barrel dimensions within .001"?

 

Remingtom Model 33

Gents,

Here is a photo of the proposed "Donor" rifle;

The barrel is of "Mid-Weight" and from an un-scientific standpoint "Looks" plenty strong and of quality manufacture (Sometime in the 1930's).

Here is another of the bolt

I want to make a little .22 mag scout rifle out of it, the money is not the point of this drill, it is simply something I enjoy doing. Taking something unique and making it uniquely "Mine", I would venture to state that there are very few if ANY .22 Magnum Remington Model 33's in the WORLD :harry: Why? Because its there! I am going to shorten the barrel to 19", and forward mount a little leupold scout scope with Warne QD rings and add some NECG banded express sights

for those "Small Game Safari's" dont ya know :bthumb: Oh, dont forget the barrel band sling swivel attachment! Anyways, I digress...

Here is what the old Model 33 stock looks like after working it over this weekend, I haven't mounted the nice Pachmayer pad (1/4" Black Decelerator" on it yet, here is what it looks like after adding the Ebony tip and "Faux" recoil lug buttons I am going to put a simple oil finish on it as shown on the finished (Except for burlap buff) shown below.

 

Here is a shot of the bolt face for any smiths out there (Armchair or Pro) with comments as to suitability to conversion from .22LR to .22MAG j, It does appear to be "Recessed":harry:

Thanks to all!

 

The link has a misprint. And so do I.
Further investigation reveals that MAX PSI for both rounds are as follows:
.22 LR 14,000 psi (NOT cup)
.22 WMR 26,000 psi
Your link is mistaken. Somebody used CUP to do the LR readings and PSI to do the .22 WMR readings.

 

The link has a misprint. And so do I.
Further investigation reveals that MAX PSI for both rounds are as follows:
.22 LR 14,000 psi (NOT cup)
.22 WMR 26,000 psi
Your link is mistaken. Somebody used CUP to do the LR readings and PSI to do the .22 WMR readings.

Been kind of an interesting read, lots of opinions, but most importantly one big bit of inaccurate info. Biggest problem was the misinformation on the max chamber pressure for the 22 LR which gsteele531 got correct!!! But the correct info was posted way back in post #26 by Hipshot and here is his link!!! SAAMI pressures What I can't figure out is where white house even got the 2 incorrect figures he posted??? The SAAMI pressure chart specifically said "All Piezo measurements unless specified" so that would be in PSI, not the (CUP) which is copper units of pressure which is the older way of measuring relative chamber pressure.
Regarding converting a Stevens Favorite my answer would be a resounding NO!!! LtCrunch said the same thing... would be looking for trouble. My thought is you would be looking at a trip to the ER to remove shrapnel from your face that used to be parts of a receiver or a case if you tried the 22 Hornet conversion. I know the 1915 Favorite could be ordered in 22 WRF, but the max pressure for that round is even lower than the 22LR. A Stevens Model 44 ought to be fine for a 22 Mag conversion as it is the big brother to the Favorite. Essentially it is an upsized Favorite, bigger, beefier frame and internals, but I would still want to make sure that everything on the 44 was tight and no slop in its lock-up.
God Bless, Frank.

 

not withstanding the potential hazards of the conversion, why in the name of John Moses Browning would one defile such a fine little rifle????! as the owner of a nice little 33 myself i shutter to think of such a thing. the cost of conversion would buy you a nice marlin or savage , i'm sure, properly barreled and chambered for the magnum. PLEASE don't do it!!!!


Roger

 

Tractorshaft,

I have no idea if you can rechamber a .22 lr to .22 mag. But I do know your cat has thumbs. And the stock looks very nice in the after pictures.

 

Cat w/Thumbs

Yeah, ha ha...

I am a "Dog Person" but as far as cats go "Tommy Ten Toes" there is a pretty cool cat. I have 2 pits and tommy thinks he is the 3rd...He is Alpha and has "ridden" cletus and lucy a few times...Ha Ha! He is what "Cat Folk" call a "Double" He likes to wear sweaters and play IN the water...