I have a Ruger Blackhawk that started as a blued 6 1/2" 357/9mm combo. We reamed the 9mm cylinder to take .357-44 Bain and Davis. It actually shoots pretty well, 1640 fps with 158 gr XTP's (23s gr of 296), the recoil is not nearly as bad as I thought it would be. My question is this, what do I need to do next? I am by no means a gunsmith and am going to ask some basic and probably stupid questions. Should I cold blue the chambers now that they are exposed metal? I have been given two additional 9mm cylinders by friends (found at gunshops that sold combo guns to folks that just wanted the .357 cylinder) and plan on leaving one in 9mm and rechambering the other to .357 Sig. What do I need to do to make sure these cylinders from other revolvers index properly? All that has been done is the rechambering, other then reblueing the cut cylinders is there anything else I need to do? Thanks in advance, my buddy that did the work has done all kind of wild mauser projects, a few Desert Eagle barrels in .357-44, and a L1A1 in 450 Marlin that he hasn't got the gas system working yet , but he isn't a revolver expert. I trust him but want to make sure we aren't skipping something important!

BIG HINT HERE: If you or your friend are not experienced at working on, or, with revolvers, the time to ask "what else needs doing" should probably come before actually test firing the weapon.

How did you cut the chambers in the cylinder? As far as getting cylinders fit and timed to a different revolver than they were originally fit for, it CAN BE a pretty entailed job even for a skilled pistolsmith. Cold blue isn't going to protect anything. It will only color the metal. If it would look better colored, cold blue it. Good luck!

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The indexing shouldn't be too much of a problem. The cylinders all go accros the same three machines that cut the latches and ratches. Your buddy definatly is going to need a range rod to check the final lockup to barrel alignment for "just in case" purposes. check all new cylinders before agreeing to buy them. What is going to be the bugger is getting end shake/headspace and barrel gap right. Each cylinder is individually fitted to it's frame.
The frames are pretty consistant as they all get broached off the ratched recess. The recoil face, the front pad and the barrel all get hit at same time.
There is no bushing that can be shimmed on the Ruger but one can be fabricated ala Colt SAA, this will give some adjustment for endshake/barrel gap. If headspace is too tight the breech end of the cylinder can be faced off, if it's too loose the face of the ratchet can be faced off, this will open the barrel gap and the end shake which will mean setting the barrel back and installing a base pin bushing.
If the barrel gets set back the two original cylinders will need to have thier muzzle faces turned back too.

If I were you, I'd get some very good measurements off the orginal cylinders, using a granite plate and a hieght gage. Then have an agreement with whom ever you buy "new" ones from that you can measure them up and if they are un usable be able to return them.

Thanks for the comments so far, like I said they are bonehead questions. malm, I understand and agree with your comment on the testfiring but it is a little late now. What do I need to do with the cylinder to protect the exposed metal in the chambers? As for as the extra two cylinders that did not come with the revolver they have not been used and I wanted to have them checked properly before using them. They were gifts so I don't have any money in them.
Any recommendations on who I should send the whole mess to to check the extra two cylinders and do what ever refinishing is needed on the interior of the 357/44 cylinder?

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The cylinder was hand cut with 357/44 reamers from PTG. The cutting was done with the cylinder out of the revolver.

You can have the cylinder hot blued. It will provide the same degree of protection that the rest of the gun now enjoys. Well, maybe "enjoy" isn't the best term...

Check your local phone book to see if you have any gunsmiths locally who specialize in pistol and revolver work. They should be able to check the cylinders and the fit for you. If you're not in too big a hurry, you are welcome to send them here. I can check them for you and let you know the extent needed to get them up and running. If interested, send me a PM.

It's pretty tough to hand cut chambers in cylinders. Make sure you and those around you are wearing good eye protection.

Personally, I wounldn't worry about the inside of the chambers not being unblued.

I can do the inspection work you need done.