Shooting 32-20's out of a 30 carbine Blackhawk

[alchemist11]

Been reading about in articles and forums how people have been shooting 32-20's out of their 30 carbine Blackhawks with great success. I was never attracted to doing it because of the fragile bottleneck case necks. BUT I was curious about how they would fit in the cylinder. Reports are that it would work with some cylinders and not others depending on the years of production. I dropped a 32-20 case into one of the chambers of the 30 carbine cylinder and it just disappeared inside it. What the hell?!?!?!? I've never heard of that before. The diameter of the chambers seems awfully generous, but with the 30 carbine case head spacing on the mouth, it fits perfectly. I've also heard that shooting 327 federal magnums in a 30 carbine is possible and a 327 case fits perfectly because it head space on the rim altho the chamber seems a bit ample. Anyway I've never heard of such outrageous specs in the cylinders of the 30 carbines. They must really have varied greatly depending on the years of production which makes absolutely no sense!

 

[Professor]

The 32-20 case head stops on the rear of a new model 30 carbine cylinder. If your cases fall through, the cylinder is not 30 carbine

 

[alchemist11]

The 32-20 case head stops on the rear of a new model 30 carbine cylinder. If your cases fall through, the cylinder is not 30 carbine

Right, I know, it should, but the 30 carbine does headspace on the rim as it should. Got me swingin!

 

[MHtractorguy]

Pictures would help a lot.

 

[NikA]

Right, I know, it should, but the 30 carbine does headspace on the rim as it should. Got me swingin!

.30 carbine headspaces on the case mouth? I'm questioning whether you tried with a .32-20 or some other rimmed .32, since the .32-20 diameter in front of the rim is practically identical to .30 carbine.

 

[contender]

Welcome to the Forum alchemist11!!!!!!


To clarify things a bit.

Yes,, the .30 Carbine Ruger revolvers,, known as the OLD MODELS were built to headspace on the case mouth. And the rear of the cylinder is too close to the recoil shield to allow a 32-20 case to be used in any of the OLD MODELS. (Old Models in .30 Carbine were built between 1968 & 1973.)

After 1973,, the NEW MODELS,, have different dimensions,, and yes,, a rimmed 32-20 case CAN be used in the NEW MODEL cylinders easily.

Basically, a NM can be loaded with a rimmed case,, while the OM can not.

 

[gasmandave]

Well that's an interesting concept.
How can a 32-20 be fired in a 30 carbine. Isn't the 32 larger than the 30? Seems it would not go down the barrel. Also what about .327 mag?

 

[Mobuck]

The 32/20 isn't actually a '32' but uses a bullet of .312" nominal diameter. At the pressures generated by 32/20 ammo, the .312" bullet will pass down the bore w/o serious pressure increase.

 

[flyingtiger]

A Forum member has done that for years, trimming case length to fit chamber in 3 screw blackhawk

 

[Professor]

Fire form the brass and size the bullets to the throats.

 

[contender]

flyingtiger,, are your sure the member has been trimming brass for an OLD model? The space between the cylinder & the recoil shield is much smaller than it is on the New Models. You may have it backward there.

I have a few .30 Carbine OM's, and none of them can accept the 32-20 cases due to the thickness of the rims.

As for bullet size; The .32-20 uses a .312 bullet. The .30 Carbine uses a .308 diameter bullet. So yes,, the bullet in a normal 32-20 is larger,, but most often, a lead bullet. For the first time it will be a bit snug. But once you fire the 32-20 brass in a .30 Carbine cylinder,, it will fireform to the chamber dimensions. Then you can easily use the .30 Carbine loading dies, AND a .308 bullet to shoot the Carbine.
Basically you are fireforming 32-20 brass to fit a .30 Carbine cylinder. It makes seating & extraction easy.

 

[Johnnu2]

Several years ago, I questioned (via telecon) Hamilton Bowen about his Ruger 30 carbine conversions to .32-20. I asked him specifically about the fact that he uses the original Ruger 30 carbine (.308") barrels. He said that they normally do. Then I asked about any potential pressure concerns with those who use the .312-.313" bullets for the .32-20; I specifically asked about lead AND jacketed projectiles; he said that there was no problems in using either of those. Now, this was probably ten years ago, so I can't say if his thinking/production has changed.
Personally, I wouldn't do it. When I had another gunsmith do my conversion, I opted for a correct .32 cal (octagon) bbl for my gun.
FWIW,
J.

 

[MHtractorguy]

Maybe not a pressure problem, but I would certainly keep my hand away from the front of the cylinder.

 

[Xrayist]

I tried this with my NM. Resized the 32-20 brass in my 30 Carbine die. Then loaded some Speer 100 gr. .30 bullet meant for the carbine round. It worked, but then found that 32-20 brass was high on the list of endangered species of the brass world. Could buy a box of loaded carbine ammo for the price of 40 rds. of 32-20 brass. As Jeff Cooper once put it, and I am paraphrasing here, "an ingenious solution to a non-existent problem".

 

[veeman]

32-20 brass won't fit the Old Model, that's a fact. I use cast bullets in my NM with 32-20 brass, usually size .309-.310, works like a charm. Use pistol powders with standard LP primers. No so loud that way.

 

[weaselmeatgravy]

I found a pic of the back of and OM .30 cylinder.

It is essentially a recessed cylinder, they just don't look like what we usually think of as recessed chambers due to the .30 cartridge not having a rim, so there is no "step" in the back of each chamber. But the firing pin groove is the giveaway. You won't see that groove in a NM cylinder because they are not recessed. Anyway, the recessed chambers cause the tight spacing between the breech face and cylinder as contender has mentioned. There is no room to accommodate the thickness of the rim on the 32-20 cartridge in an OM cylinder without modification.

 

[needsmostuff]

It's an exercise I gave up on. After fireforming then resizing with 30 carb dies I never could get proper neck tension,,,, Not even with .313 bullets! Could be just my dies but I concluded it was because the thickness of the 30 carb brass. With the much thinner 32-20 brass the ID was never small enough.
Like Xrayist I decided my 32-20 brass was more important to me as is and 30 carb brass is easy to find.
Plus it dawned on me I have a dedicated ,one cylinder Buckeye in 32-20 that is virtually the same gun .
My 30 carb now shoots only 30 carb and my 32-20 gun shoots only 32-20.

 

[DutchV]

Several years ago, I questioned (via telecon) Hamilton Bowen about his Ruger 30 carbine conversions to .32-20. I asked him specifically about the fact that he uses the original Ruger 30 carbine (.308") barrels. He said that they normally do. Then I asked about any potential pressure concerns with those who use the .312-.313" bullets for the .32-20; I specifically asked about lead AND jacketed projectiles; he said that there was no problems in using either of those. Now, this was probably ten years ago, so I can't say if his thinking/production has changed.
Personally, I wouldn't do it. When I had another gunsmith do my conversion, I opted for a correct .32 cal (octagon) bbl for my gun.
FWIW,
J.

I don't have a .30 Carbine Blackhawk here (not yet, anway) but I'll make an observation. The overall barrel profile of the .30 looks about the same as the other Blackhawks. So wall thickness of a .30 barrel will be a lot thicker than other calibers, and definitely a ton thicker than a purpose-built .30 needs to be. That's how it can handle a slightly larger bullet safely.

 

[Hondo44]

By simply recessing the OM 30 M1 cylinder chambers for the thickness and diameter of the 32-20 and .32 Mag/.327 Mag case heads they will chamber and shoot fine. The 30 carbine will still headspace on the case mouth just like they normally do in both OM and NM 30 M1 cylinders.

 

[Elfego Baca]

I use the same bullet mold for my M1 carbine and Marlin 1894 32/20. Bullets sized to .312.