Question about Old Model (three screw) Blackhawk revolvers

[cee_Kamp]

I don't know very much about the history of Old Model Ruger Blackhawks.
Did Ruger ever produce a factory Blackhawk Old Model .357 Magnum/9mm convertible?
I have an acquaintance with a blued Old Model .357 Blackhawk.
He would like to add an additional cylinder in 9mm. (9X19/9mm Luger)
Is there such a thing as an factory Old Model 9mm cylinder?
Or is it something that requires a Custom Revolver Smith to make from scratch?

I've fitted extra cylinders in New Model Blackhawks, but I don't know enough about the
Old Model Blackhawks to tell him if it's something that can be done on an Old Model
using used second hand factory parts, or a full-on Custom made cylinder.

Please advise.
Thanks in advance!

 

[BoggusDeal]

Yes, they did make convertible Blackhawks. Finding a 9mm cylinder may be tough and expensive but they are out there. A want ar here might find one or I have seen them on eBay.

 

[GasGuzzler]

Expect to pay $200 or so for an Old Model 9mm cylinder. Set up an alert on eBay. Also make sure and learn how to ID an OM from a NM cylinder.

 

[contender]

Yep,, Ruger did make a factory issued Blackhawk convertible in 9mm/.357. There were made from 1967 until 1973. The non-prefix ones are rarer & require a factory letter to verify them. On those the cylinders will have the last 3 digits of the serial number in electric pencil on the face of cylinders. There were about 1500 of this variety. Then the prefix version,, there were many thousands made.

As noted above,, you can search for a spare cylinder,, but there is a difference between the NM & the OM. The OM will have a shorter cylinder boss vs the NM. And expect to pay for a proper cylinder. As noted,, they approach $200 quickly.

A custom is a potential route. But a good search can turn them up as well. You do have to have a correct cylinder,, AND the OAL needs to be the same or a few thousands longer to allow fitting. Same as with a NM cylinder.

 

[cee_Kamp]

Thanks for the information!
My internet friend will be doing the locating/buying/fitting of the Old Model 9mm cylinder.
I just didn't want to send him on a "mission" for locating one, if the factory never made any.

 

[loaded round]

Yes Ruger did make a Blackhawk convertible in 357/9mm. I have one that I purchased way back some 20-25 years ago. 61/2 barreled OM Blackhawk with rear sight ribs. I also have convertibles in Ruger Vaquero's in 45 Colt/45 ACP, and 44-40/44 Spl. Love to find one in 10mm/40 S&W next.

 

[cee_Kamp]

I have one of those Lipsey's 10mm/.40 Blackhawks with the 6.5" barrel.
Also a cosmetically rough Blackhawk in .357 where I added a carbon steel 9mm cylinder, and a Birdshead grip frame.
And a convertible Single Six in .22LR/.22 Mag.
Does an Old Army count as a convertible if you added a cartridge cylinder?

IMG_20250326_123346864 by cee_Kamp 32ACP, on Flickr

IMG_20250326_123405249_HDR by cee_Kamp 32ACP, on Flickr

IMG_20250326_123900903_HDR by cee_Kamp 32ACP, on Flickr

IMG_20250326_124024009_HDR by cee_Kamp 32ACP, on Flickr

IMG_20250326_123524979_HDR by cee_Kamp 32ACP, on Flickr