'73 win project question

[Isom]

Want to do something different. Want to convert a Win. '73 in 32-20 t0 25-20. I know they are made in the '92, just want to be a little different. Looked to see if the pressures were that much different. could only find the 25-20 in PSI, and the 32-20 in CUP . Does anyone know the pressures of both in PSI or CUP, or a conversion formulae. I figure just a barrel reline and chamber ream. The host rifle will be an Italian import, NOT an original.
Thanks,
Isom

[Coffinmaker]

   Oh Boy Oh Boy 

Actually, Nadia Clue.  Ima dry hole.  Except and Howsome Ever.  The Uberti 1873 Replicas are proofed for 357 Manglem and 44 Mangler.  I seriously doubt either a 32-20 or 25-20 could even tickle those two for pressure.  I would precede just like you know what yer dooin.  I know I would.  Inna heart beat. you betcha.

[Major 2]

I deal with it in Milsurps...

this may help you   https://www.shootingsoftware.com/ftp/psicuparticle2.pdf

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[Pettifogger]

Are you talking a real Winchester 73 or a Uberti?  If it is a real 73 don't bother.  It is not made for high pressure rounds.  Winchester made "hi-velocity" loadings for the .32-20, 38-40 and .44-40 years ago and labeled the box for 92s only.  People were just as stupid then as they are now and didn't read the box so Wichester had to stop producing the high pressure rounds.  The Uberti 73s are really spotty for reliablilty in .32-20.  Uberti cheats on the design and uses big bore parts in the .357 versions.  Then they tried to modify the .357 parts to the even smaller .32-20.  Sometimes they work, sometimes they don't.

[Abilene]

Are you talking a real Winchester 73 or a Uberti? ...
... The Uberti 73s are really spotty for reliablilty in .32-20.  Uberti cheats on the design and uses big bore parts in the .357 versions.  Then they tried to modify the .357 parts to the even smaller .32-20.  Sometimes they work, sometimes they don't.

Isom mentioned above it would be Uberti.  As for the .357 parts, my 32-20 is suffering from extraction issues as we speak.  I had the extractor tweaked when it was new (he shaved a bit from the bottom of the extractor so it sat a bit lower) but after a couple thousand rounds it has problems again.  But, if Isom can get that issue straightened out with it in 32-20, then at least the rim of the 25-20 would be the same and that should work okay after conversion.  I would suggest a liner in the mag tube.  I have a fiber liner which does help but would opt for an aluminum one next time as it is thicker.

[Pettifogger]

Yep they have extraction problems because the .357 bolt face is simply to big.  The cartridges also rattle around in the carrier since .32-20 is smaller than .357.  On my Uberti I wound up putting the bolt in a lathe and turning the head down then relocated the extractor so it was set for the .32-20.  A mag tube liner is almost a necessity.  Then I sleeved the carrier and recut it to fit the .32-20.

[Abilene]

Could you just cut the extractor notch a little deeper on top of the bolt and add a little material to the tab on the bottom to get the same result?  I'm thinking on sending my bolt off to somebody to do something to it.  Jim Bowie told me Cowboys and Indians once made a 32-20 aluminum carrier,but not many.  Sure would like to find one of those.

[Pettifogger]

Yes you can deepen the extractor notch.  I talked quite a bit with Jim about a new carrier.  The problem was that if you made the carrier to fit the .32-20 then the stock Uberti bolt head would not fit through it.   And, most people would not machine the head like I did so he scrapped the project.

[Coffinmaker]

   Howdy Larsen E.   

I are some glad Pettifogger chimed in.  The cartridge pressure was my only valid input.  In all the years I worked on CAS Toggle Link rifles, I did not have opportunity to work on a 32-20.  I did have a shooting partner at one time, whom had one and had intermittent feeding/extraction problems but I was never asked to work on it.  I chalked it up to him constantly trying to run semi-wadcutters thru it.

Thanks again for your knowledge Larsen E.

PS:  A mag tube liner is an extremely good idea with 38/357.  I can well see where it would become necessity with a 32-20.

[Isom]

Thanks for all your input. I've got 2 Uberti 32-20 rifles from 10-12 yrs ago. One new one was used, both worked great with no extraction problems. Loading them was a pain past about 6-7 cartridges. I don't think they had the magazine sleeves out yet. I ordered 2ea. Win.'73 small caliber, magazine tubes, springs and followers. The od. of the tubes were smaller than the id. of the Uberti  mag tubes. They use the same tube for everything  from .45 to 32-20. Roughed the od.  of the smaller tube and the id. of the mag. tube with 60 grit paper cleaned with acetone, cut to length, used clay in the main mag. screw threads near the muzzle. Used safety wire to keep it pretty much centered, used the Midway jell glassbedding  compound to glue them in. Overnight drying. Had to make an adapter for the hole in the fame because it was set up for the large follower . I was good to go. I used one for over a year as main match rifle and never had any extraction problems. Although I did find out that different manufactures all had different case OAL for the same cartridge,,,,,,, That's another story. 
YMMV,
Isom

[Abilene]

I guess when ol' Isom sleeves a mag tube he doesn't mess around! 

[Pettifogger]

Yeah seems like the hard way.  The aftermarket aluminum tube's OD is the ID of the Uberti tube.  They just drop in.

[Major 2]

I had somewhat the opposite occurrence

I have a original 73 in 32/20 made in 1891. It had some spring binding.
 After a detailed clean (it had been in the same collection since the early 60's ) I discovered the spring was the near Dia. as the inside Magazine bore and it dragged, and the follower was a carved wood piece  probable replaced many years ago with incorrect spring.

I ordered a 32/20 replacement spring & follower from Winchester Bob.... and Bob was my uncle so to speak 

[Isom]

Pettifogger;
they didn't have the mag liners when I did those two. If they did, I didn't know about them,. I wish I did though.  I'm using Uberti's NOT my originals. Originals made in 1890 and 1892 . The one from 1892 is a kind of a parts rifle, from ebay and Homestead parts.
Isom

[Isom]

Pettifogger,
when I sleeved the mag tube, I don't think they had those mag sleeves out yet. If they did, I didn't know about them. I've got 2 '73's. in 32-20, an 1890 and a 1892. The'90 is all original, the '92 is a parts gun from ebay, Bob's and Homestead. It was a mess when I got it. New bbl and wood, aged to look like the rest of the gun. Not to shabby for a "tinkerer"
Isom

[Isom]

I don't know what happened, when I wrote the first one I didn't check to see if it went through. When I went back this afternoon, I didn't see it, so I wrote it again, and when I hit post, both came up. Scamper juice was not involved !   
Isom

[Pettifogger]

Oh, Oh, maybe it is the virus.  How many fingers am I holding up?  Is your head warm?