9mm cylinder in Blackhawk

[KeithB]

I have a .357 Blackhawk. I saw a 9mm cylinder on one of the auction sites. Got a lot of 9mm ammo. I'd like to buy it and use it. What issues might I run into? How closely are the interchangeable cylinders fitted at the factory?

 

[RicinYakima]

Not sure, but I have done about 10 45ACPs to 45AR in 45 Colt Blackhawks. As long as they are old model to old model and new model to new model, the only issue I have seen is barrel/cylinder gap. Too small put it in the lathe, to large just shoot it anyway. FWIW

 

[CZ93X62]

No experience with the 9mm/357 swap-cylinder BHs, but Iv've had 2 of the 45ACP/45 Colt versions. The 45 ACP cylinders got a lot more use than the 45 Colt cylinder did--on both guns. Accurate, trouble free, and fun. I regret selling off the the 4-5/8" edition, it was a great field gun. It took a new Model 625 to ease my grief over the BH's departure.

 

[KeithB]

I have a limited amount of .38 and .357 brass. I use the .38s in my M10 and save the .357s for my GP100. I have a LOT of 9mm brass and a fairly good supply of loaded 9mm bulk pack ball ammo. The only 9 I own is a HiPower. Wonderful gun that like all semis makes me bend over to pick up my brass outdoors and surrender it to the range owners indoors. While not a big fan of SAs the recoil of a 9mm equivalent .38 load in a Blackhawk is easily manageable. Like you guys with the .45s, I would probably shoot a lot more rimless auto cartridges than traditional rimmed rounds.

 

[JustJim]

I once bolted one up in the Ransom Rest just for fun. In general, if you plotted the accuracy of the loads tested in that gun (9mm, 38, and 357), the 9mms were mixed in with the 38s, with the 357s standing higher. It just depended on the load, but in general the higher-velocity self-defense loads were more accurate than the surplus stuff.

 

[Ian]

I can't help with the question but I know two things: I have some neat .45 ACPs but my favorite and one of the best shooting of all is a single-action Peacemaker clone. The other thing is a good machinist can probably make it work.

 

[Walks]

Some years back I shot Cowboy with a guy that tried the 9mm cylinder from his NM Blackhawk convertible(4 5/8") in his Big Vaquero in .357Mag. It indexed properly and it kept all shots in the black at 50ft. So he bought another Blackhawk convertible(6 1/2") and put that cylinder into his other Big Vaquero.
Used a bit less powder and a lighter 125gr bullet, less recoil too.
So if it fits, do it.

 

[Thumbcocker]

The important thin is that the 9mm cylinder be as long or (preferably) longer than your .357 cylinder. If shorter you have a problem. I fitted one to a .357 by starting with a cylinder a few thousandth longer and using a flat sharpening stone and then fine emery cloth on a piece of glass until it just fit in the gun. It indexed and locked up fine.

If you intend to shoot cast in the gun the cylinder will need to be honed a bit; otherwise lead and boolit lube will build up where the case headspaces on the chamber and the rounds won't seat. If you don't want the cylinder honed you can use a .38 special or a .357 empty case to clear the cylinder once in a while but it is a pita.