The seldom seen Uberti SAA .32-20/.327 Magnum convertible

[Tom K]

I have an uncommon Cimarron-Uberti SAA in .32-20 with an extra .327 Federal Magnum cylinder. Uncommon because they don't make one. Here it is with the .327 cylinder installed.

.327 on the left, original .32-20 on the right.

Interestingly Cimarron makes a 7/8 scale SAA called the Model P Junior available with .32-20 and .32 H&R Magnum cylinders. But, they don't offer the full size SAA in .32-20 with an extra .32 H&R cylinder (or .327), so I decided to make one. Poking around on various websites I found that Uberti has made .22LR/.22WMR revolvers based on their full size frame. At one time you could buy parts such as cylinders from them but I'm not sure that is still the case.

Couple of years ago I bought a .22 cylinder from Uberti but found that so the centerfire hammer could be used without alteration, Uberti had drilled the .22 chambers at a slight angle to allow the hammer to hit the cartridge rim. I wasn't sure if enlarging the chambers to .32 caliber would clean them up so I sent it back.

At any rate, I found a .22WMR cylinder on eBay with straight chambers and bought it. It was pretty much a drop-in fit to my Cimarron .32-20, so I took them to my gunsmith and had him do what needed to be done. As you can see in this before/after comparison pic, the .22 Mag cylinder originally had a lip on the edge in case of a case rupture. That was machined away and the chambers enlarged and reamed to .327 Federal Magnum. A little bit of tweaking to the timing and presto! .32-20/.327 Mag convertible.

In this gun, muzzle velocity of the .327 is about double that of .32-20 with commercially available ammo, American Eagle at 1590fps with a 100gr JSP vs Black Hills Cowboy at 790fps with a 115gr lead flat point.

 

[pawngal]

Very cool and interesting. I have a Cimarron Lightning, 3 1/2 in. with the 32-20 and .32 H&R cylinders. Would be neat to add the .327 option.

 

[Muley Gil]

I have the Model P Jr & I reamed the .32 H&R Magnum cylinder to .327 Federal Magnum. I haven't fired any .327 ammo through it yet.

 

[jeffrefrig]

I have the Model P Jr & I reamed the .32 H&R Magnum cylinder to .327 Federal Magnum. I haven't fired any .327 ammo through it yet.

I'm curious about that. I have a .327 FM revolver, but it'll shoot any .32 caliber cartridge. Whatever you did, was it for the little extra length? Or are the cases larger diameter for the FMs? I love the caliber (Fed Mag). In the gun I have, 6" full lug GP 100, it's like shooting a .22 LR on steroids. Virtually no kick; much less than a .38 Spl. out of a K Frame.
That's a nice Uberti up there. Pretty cool what you did, OP. I may have to go shopping. Trying to decide on replacing the Uberti I had & "gave" away, or a SAA in .44 Mag. Think a .32-20 would be a nice one to play with.
Wait, does that -20 have something to do with it?

 

[Tom K]

I'm curious about that. I have a .327 FM revolver, but it'll shoot any .32 caliber cartridge. Whatever you did, was it for the little extra length? Or are the cases larger diameter for the FMs? I love the caliber (Fed Mag). In the gun I have, 6" full lug GP 100, it's like shooting a .22 LR on steroids. Virtually no kick; much less than a .38 Spl. out of a K Frame.
That's a nice Uberti up there. Pretty cool what you did, OP. I may have to go shopping. Trying to decide on replacing the Uberti I had & "gave" away, or a SAA in .44 Mag. Think a .32-20 would be a nice one to play with.
Wait, does that -20 have something to do with it?

In a manner of speaking, yes that -20 has something to do with it. The .32-20 is a blackpowder designation meaning a .32 caliber bullet, backed by 20 grains of black powder. Similar to .45-70 or .44-40. The case was designed with a bit of taper to allow easier chambering even when fouled by black powder residue. Here's a pic showing the .32-20 on the left, .327 in the middle, and .357 magnum on the right.

What it boils down to for me preferring the .327 over the .32-20 is ease of reloading cartridges. Since the .327 is a straight wall case, carbide dies are available that don't require lube. As far as I know, nobody makes carbide dies for tapered cases like the .32-20.

 

[Alk8944]

Tom K,


I obviously don't know when you had the work done, but Cimarron currently has a .32-20/.32 H&R convertible in the full size SAA. If the .32 H&R was available it would have been much less expensive to buy a .32 H&R cylinder and re-chamber it to .327 Federal than to convert a .22 cylinder.

 

[Tom K]

Tom K,

I obviously don't know when you had the work done, but Cimarron currently has a .32-20/.32 H&R convertible in the full size SAA. If the .32 H&R was available it would have been much less expensive to buy a .32 H&R cylinder and re-chamber it to .327 Federal than to convert a .22 cylinder.

Do you have a link to that? I have looked through Cimarron's website and see only the small frame Model P Jr. and Lightning as a .32-20/.32 H&R convertible.

 

[Brooks]

Did this 327 cylinder come stock with the gun, or did you buy the gun used and someone reamed it out from 32 mag to 327?
If it came like this from factory, it means the Uberti Cattleman/ Cimarron Model P can take pressures much like a Ruger in 30 carbine.

 

[Tom K]

Did this 327 cylinder come stock with the gun, or did you buy the gun used and someone reamed it out from 32 mag to 327?
If it came like this from factory, it means the Uberti Cattleman/ Cimarron Model P can take pressures much like a Ruger in 30 carbine.

If you re-read the first post, I stated that the .327 cylinder was a Uberti .22 Magnum cylinder that I had my gunsmith rechamber.

 

[Brooks]

How does the 327 shoot that revolver?

 

[silicosys4]

That's a neat combo.
I'm curious what the .32-20 is capable of out of the model P junior.
I know out of a SAA size Gun it's capable of a lot more than cowboy loads give.

 

[Ivan the Butcher]

You can get a PDF of the Lyman #44 on line. It has the Older Carbine loading data. (Considered unsafe for antiques but would be fine for newly made guns.) My 1902 first change from 1902 and my Colt PPS from 1919 only get lead/Cowboy loads. My 1990's made 1895 Marlin 32-20 get Jacketed Carbine loads, very similar to M-1 Carbine loads.

Ivan

 

[Brooks]

I'm asking if you have shot the Uberti Cattleman with this 327 cylinder and ammo. If the Uberti Cattleman will take the added pressure of the 327.... up from 32mag pressures. I'm assuming it can, but you probably should resist doing so.

 

[Tom K]

I'm asking if you have shot the Uberti Cattleman with this 327 cylinder and ammo. If the Uberti Cattleman will take the added pressure of the 327.... up from 32mag pressures. I'm assuming it can, but you probably should resist doing so.

Reading is your friend. Once again, re-read the original post.

"In this gun, muzzle velocity of the .327 is about double that of .32-20 with commercially available ammo, American Eagle at 1590fps with a 100gr JSP vs Black Hills Cowboy at 790fps with a 115gr lead flat point."

 

[Brooks]

No need to keep telling me to read. I can read. I am asking directly if you have fired 327 from the Uberti and chrono'd the velocity, how many rounds, or just stating what you think the velocity is.
If you are experiencing signs of primer flow-back, possibly locking up the cylinder.
I am asking if this Uberti can take the pressure of the 327.
I can and have loaded 32-20 up to that 327 velocity in a T/C Contender and a Marlin rifle...about 1900fps

 

[Muley Gil]

That's a neat combo.
I'm curious what the .32-20 is capable of out of the model P junior.
I know out of a SAA size Gun it's capable of a lot more than cowboy loads give.

I use a handload of a 100-115 grain bullet over 4.5 grains of Unique in Remington .32-20 cases in my Model P Jr.

 

[Brooks]

Muley, I think you could go to 5.5 grains of Unique in 32-20 and you would bring your pressure up to what a 32mag is. I don't know about going (further) with 327 pressure in the Ubertis. This is why I am asking.

 

[Tom K]

No need to keep telling me to read. I can read. I am asking directly if you have fired 327 from the Uberti and chrono'd the velocity, how many rounds, or just stating what you think the velocity is.
If you are experiencing signs of primer flow-back, possibly locking up the cylinder.
I am asking if this Uberti can take the pressure of the 327.
I can and have loaded 32-20 up to that 327 velocity in a T/C Contender and a Marlin rifle...about 1900fps

I don't mean to be obstinate, but all of the questions you have asked were answered in my first post. You initially asked if the .327 cylinder was factory or not and I pointed out that I had stated that it was a rechambered .22WMR cylinder. Then you asked if I had shot the gun with .327 ammo and I quoted the velocity figures from my first post:

"In this gun, muzzle velocity of the .327 is about double that of .32-20 with commercially available ammo, American Eagle at 1590fps with a 100gr JSP vs Black Hills Cowboy at 790fps with a 115gr lead flat point."

Then you ask again if I had actually shot the .327 or was just guessing at velocity figures. To me it's pretty clear that it means that those are velocities achieved "In this gun..." (the pictured Cimarron SAA with the factory .32-20 and custom .327 cylinders) with the noted factory ammo. I don't see why that's so hard to understand.

Regardless, here are some data for your viewing pleasure. Velocity measurements were taken with a LabRadar chronograph. The targets are on 11x17 paper with a 1" grid.

American Eagle .327 Federal magnum with a 100gr JFP bullet.

Black Hills .32-20 with a lead 115gr RNFP bullet.

Note that the .32-20 target was shot several years earlier at a slightly different distance, and standing instead of from the bench. The aiming diamond is a larger size, which I prefer when standing. I also shot 13 rounds instead of 12, probably just finished out a box of ammo. The point of impact is lower which might be due to the difference in velocity (although slower rounds typically impact higher due to more time in the barrel during recoil). Or it might be because I was standing vs shooting from the bench. Kind of an apples/oranges situation. But, none of this affects velocity readings.

Regarding what a Cimarron SAA can take, I feel comfortable shooting .327 out of it. There have been any number of people on this forum who have made their own .327 S&W revolvers using a rechambered K frame .22LR cylinder, without any special treatment. A SAA cylinder is quite a bit larger than a K frame cylinder so there is substantially more "meat" around each chamber.

As for higher pressure .32-20 loads, Brian Pearce wrote an article on .32-20+P loads in the April-May 2023 issue of Handloader magazine. I'll quote a bit of it here:

...
[FONT=&quot]Generally speaking, handloads that are within the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) pressure guidelines can push 100- to 115-grain cast bullets to 900 to 1,000 fps from revolvers with 4¾- to 6-inch barrels. However, when handloaded to +P-style pressures (as outlined later), it can push the same weight bullets to more than 1,300 fps, which approaches the performance of the modern .327 Federal Magnum, but is operating at 15,000 psi less pressure and as a result, produces less muzzle report![/FONT]
[FONT=&quot]... [/FONT]
[FONT=&quot]I do not want to delve into great detail about the strength of different sixguns, but guns that fall into the "strong" or "+P" category include all Colt Single Action Army revolvers produced after the year 1900 (or above serial number 192000), the Freedom Arms Model 97, USFA and Uberti SAA-pattern guns, the Colt Army Special and Official Police, the Freedom Arms Model 97 and Ruger New Model Blackhawk. Revolvers that I generally limit to "standard pressure" loads (16,000 CUP), or slightly above, include pre-1900 era black-powder production Colt Single Action Army, Model 1878 Double Action, Models 1892 and 1895 New Army and New Navy, Police Positive Special and the Smith & Wesson K-frame Hand Ejector.[/FONT]

[FONT=&quot][emphasis added][/FONT]
[FONT=&quot]
[/FONT]*Not sure what happened but I edited this post to re-add the pictures.

**I will also note that the Uberti Cimarron Jr .32-20/.32 H&R combo is a smaller frame than the Uberti SAA, about 7/8 scale. I don't know if I would feel comfortable firing full .327 ammo out of this one. Muley Gil, have you ever given it a try?

 

[jreidthompson1]

It appears that the photos failed to upload for the post with data

 

[Muley Gil]

Muley, I think you could go to 5.5 grains of Unique in 32-20 and you would bring your pressure up to what a 32mag is. I don't know about going (further) with 327 pressure in the Ubertis. This is why I am asking.

I have a couple of pre-World War ONE S&Ws and I wouldn't want to mix up the loads.