Blackhawk conversion

[Bruce51]

I have a new model Blackhawk in .357 I enjoy looking at but I shoot it poorly or it is not very accurate. Just pick one it doesn't really matter.

Has anyone ever tried to convert one to .30 carbine, 32 H&R 32-20 or .327 Federal?
I know it may not be cost effective but I enjoy projects.
If all I need is a barrel and cylinder then I'm good to go.
Enlighten me on the concerns and issues. I'm already seeking out parts.

Bruce 51

 

[Bruce51]

The .30 carbine cylinder is too long to fit in the frame without some modification.
Might need a 32-20 cylinder to make this work.

 

[hittman]

You'll be money ahead to buy another complete gun in the caliber you choose.
Or try different ammo in 357 or shoot 38 Special through it.

For me, if I don't shoot a gun well I assume it's ME and there's the challenge ( excuse? ) to shoot it more and become proficient with THAT gun.

Maybe different grips too? Don't know your experience level but for me, a double action guy, the single actions took some learning.

 

[woodsy]

Would probably end up costing more than a brand-new revolver, all said and done. And then the problem is most likely the shooter, as hittman said.

 

[Bruce51]

I admitted it could be me. However I have tried many different bullets, powder charges and cases.
The rifling is good and the cylinder throats are the perfect size.
I have shot it standing, sitting with my wrists supported and it will not shoot a decent group.
I have shot various handguns for fifty years and shoot once a week since 2016. I'm not new to handguns or BH's by any means. Every trip to the range with this BH is a disappointment.
It's time to sell, trade or modify to suit my needs.

I haven't found a replacement locally so I asked if anyone has done a conversion.
It's a simple question.

Bruce

 

[Hondo44]

The .357 Rugers I own are all very accurate. Have you had someone else shoot yours to see how accurate they can shoot it? Is yours a mid-size Flattop Blackhawk or a large frame Blackhawk?

If it's a large frame you have two likely sources for Ruger factory cylinders and barrels:
1. Ruger .30 carbine, and
2. there's a Ruger .327 eight shot that was produced for a short time.

I mention that because if you could find a Ruger cyl and barrel, that would be a much less costly way to go. Custom cylinders and barrels are pricey.

Once you have a .327 or .30 M1 carbine cyl and barrel, with slight modification to the cyl you can use all cartridges you mentioned from the same cyl. and barrel. The New Model .30 M1 cyl takes slightly less work because it has enough headspace for 32-20 and .32 H&R/.327 Federal case rims. Chamber measurements vary slightly but a little honing of the chambers will allow all those cartridges to work: a little honing in the neck area for the .32/.327 and in the body area close to the rim for the 32/20. Or you can rent 32/20 and .327 reamers to clean up those areas.

The .308" barrel rifling dimensions are close enough to work well. The .312" bullets may tend to raise pressure negligibly in the smaller .308" barrel although of no consequence in the robust Ruger cyl and way under its max pressure limits. And you may have some leading with lead bullets that are too soft depending on hardness. But you'll have good accuracy.

 

[hittman]

Since you're experienced I'd sell or trade it, Something will show up you're interested in.
But … it's YOUR money and you're welcome to throw as much at that gun as you like,
For me, customized guns don't trip my trigger but ….. others really get excited over them.
Best of luck with your decision.

 

[Bruce51]

Good answer on topic. Right now I know that the .30 carbine cylinder is too long.
I have fired the 327 in the 30 carbine. It fits, it fires, but the .312" bullet is too large for the cylinder throat and forcing cone.
The amount of build up at the forcing cone was down right scary amounting to an additional restriction.
I fired lead bullets at 900 fps just to test. I would not recommend this practice.
BTW this is a New Model BH maybe from the 1970's.

Bruce 51

 

[contender]

Bruce51,, re-read Hondo's post above. The .30 Carbine Ruger factory barrel & cylinder will fit your gun. All NM full sized Blackhawks have the exact same frame size.

That said,, before I'd throw in the towel & all, I agree that having someone else shoot it,, with just factory jacketed ammo to see what happens.

Lastly,, the things you haven't mentioned "thread choke", or having slugged the barrel. Either one can be a potential accuracy killer.

 

[Bruce51]

Just saying that I have a .30 carbine cylinder from a three screw and it is longer than the NM .357 cylinder.
Maybe a NM 30 carbine cylinder is the same.
I did some measurements just to find out.
NM window top 1.857" Bottom from the left side 1.872"
Three screw top 1.880" bottom 1.887"

NM to barrel shank 1.750"
Three screw 1.774"

NM Cylinder length w/o ratchet 1.640"
With ratchet across the bushing 1.945"
Three screw length w/o ratchet 1.747"
With ratchet and bushing 1.965"
I know barrel shanks can be altered, cylinders shorten and frame windows can be opened up.
Also comparing a Three screw to a NM may not be exact but it's what I have to work on right now.
Just trying to find out more information. It would be great to find a .32 barrel and a .30 carbine cylinder as that would work well to convert. Thanks for the info so far.
Bruce 51
Had to edit a measurement oops!

 

[Bruce51]

As far as trying factory ammo or another shooter I am way past having more interest in this revolver as a .357. Thank you for understanding.

 

[contender]

Ok,,, we'll forget about trying to fix the .357 as is.

You are comparing an OM Cylinder with the NM window space.

The way Ruger manufactured the 2 models of their cylinders is different. The OM is a bit longer,, and why we can't chamber the 32-20 ammo like we can do in a NM. A NM cylinder body is a bit shorter. which allows some folks who wish for a rimmed .30 cal to use 32-20 brass. I own only an OM in .30 Carbine, and no NM's of that caliber. But due to that difference,, I'd buy a NM just for kicks to try it.

So,, in your case,, your parts are a little different. BUT,, if you do try using the .30 Carbine OM cylinder in any NM frame,, it will require machining the rear face to allow for a rim of whatever caliber you choose. Then you may run into an issue with the ratchet dimensions.

But if you have a NM frame,, and got a NM cylinder & barrel,, you can easily do a swap if you have the skills to correctly set the barrel, and time the cylinder.

 

[Bruce51]

Thank you contender! This is exactly what I need to know.
Now if I can find the barrel and cylinder for a good price I can get to work.

Another question about possible barrel candidates.
If I found a .30 carbine barrel who might be the right person to convert/rifle it to .312".
Anyone have this done in any caliber and what was the cost?
Just keeping my options open as I search for parts.
As far as the cost of this project verses a new .32 I will have a cylinder and barrel to sell to partially recoup my replacement parts cost.
Bruce 51

 

[Hondo44]

There's one guy the popular gunsmiths used for barrel reboring: Redmans in Washington state. But I think he retired and there's a new go to guy. Google Jack Huntington, a great Ruger gunsmith and he can give you a recommendation.

 

[Bruce51]

Thank you for the information. I hope that finding parts is not mission impossible. I've had good luck find parts I need at the right time. This may be the the hardest quest yet.
Projects;
Keeping retirees alive because we need something fun to do.