Blackhawk convertible 357/9mm and 357 Sig ?

[Scott in NCal]

Is it possible to rechamber a 9mm cylinder to 357 Sig ? My Speer reloading manual lists the 357 Sig as having higher pressure than the 357 Mag, but the Blackhawk seems massive. I see 9mm cylinders on fleebay but understand the model was made on large frame,medium frame, flat top ect. How can I tell what cylinder fits my gun ? Is this conversion do-able. By do-able I mean safe and affordable. Any idea who may do this sort of work and the cost ? Can I just send the cylinder or does the revolver have to go ? My friend works for a private security company and gets all the 357 Sig ammo he wants, but he has to return the empties. I am to old, have no interest, was never any good at it anyway, to crawl around looking for empties, so a semiauto is out. Any comments, ideas or suggestions would be appreciated. Thanks Scott

 

[contender]

Welcome to the Forum.
Can you chamber a 9mm cylinder for a 357 Sig? I'd say it's most likely a yes to the possibility. Would a Ruger handle the pressure??? A regular Blackhawk would be an acceptable gun to use for conversion. I'm not sure about the medium framed, (also the same as the Flattop's) & their strength & the pressures of the Sig caliber.
For fit,,, a NM Blackhawk 9mm cylinder so sold to fit an identical model will most likely work if the OAL is the same. If you buy one a tad longer, it can be filed down to fit. Timing is USUALLY ok,,, but to be sure,,, check with a gunsmith.
Any of the custom gunsmiths that work on SA handguns can likely do the work,, but it's NOT cheap or quick.
But here is the biggest issue I see.
The Sig is a bottleneck caliber, and as such, a revolver cylinder has to be bored to certain specs. In the past, many bottlenecked calibers that have a sharp shoulder like that have issues. Sticky cases, split cases, proper seating depths, trimming brass,, are a few things that pop up.
Back in the 1970's the 357/44 Bain & Davis was first developed by necking a 44 mag case down to 357, and used a bored out 357 cylinder. Due to case problems,, they first tried to use a plastic "collar" to support the neck/shoulder area. Dismal results. Nowadays, they use a shallower & longer taper to achieve it.
Due to all the different issues (problems) such endeavors present,,, you rarely see any revolvers using any caliber that has such a sharp shouldered design.

 

[Chief 101]

The conversion is doable but there is a 357/44 Bain & Davis semi wildcat cartridge that is tailor made for this purpose... http://www.hornady.com/assets/files/reloading-manual-data/357-44%20Bain%20&%20Davis.pdf

 

[6GUNSONLY]

If a body wanted such because he shoots the .357 Sig in autopistols, I can see the appeal, sort of... Otherwise I don't think it would do anything the .357 wouldn't do better. JMO, of course.

 

[tinman]

I don't think it would do anything the .357 wouldn't do better. JMO, of course.

I can............cost more to shoot.......... :roll:

 

[Diamondtreo]

I believe B&D are still in business located in San Gabriel, Ca. http://www.yelp.com/biz/bain-and-davis-gun-shop-san-gabriel Here is another Ruger forum with a guy who had them convert a 9mm cylinder http://rugerforum.net/ruger-single-action/35933-9mm-now-357-44-bain-davis.html. I might do the same thing if I can find another 9mm cylinder to play with to go with my S&W Mod 28-2 that has been converted as well.

 

[contender]

Folks,,, I mentioned the 357 B&D as it's development was a good study in the problems associated with sharp shouldered pistol calibers in a revolver cylinder. The OP was NOT asking about the 357 B&D,,, but only the 357 Sig. If you study his post,,, I believe it was because they have access to a good supply of ammo.

 

[Chief 101]

I realize that, but there is a negative gain in ballistics going from 357 mag to 357 sig and the issues involved using rimless, crimpless and bottleneck cases in revolvers. The reason I mention B&D is because at least its a proven cartridge with tested loading data in revolvers. For the price of chambering a cylinder you can buy a whole lotta ammo...

 

[s4s4u]

I'm sure it could be done, but I'd also be concerned about setback.

 

[Scott in NCal]

I think some of you are missing one of my main points, that is through a friends work, for free, I can get all the 357Sig ammo I want, so long as I return the brass. A much easier task with a revolver than a semi auto. I am full on aware of isues using bottleneck cases in a revolver. What got me thinking about this was what I read about the 357 Sig in the Speer reloading manual 14. "Other bottle neck cartridges have enjoyed only limited popularity. However, the design offers advantages over the more common straight-taper design". What I wondered would those advantages be ? I kept reading. "The cartridge headspaces on the case mouth, not the shoulder as many people think. The shoulder angle and and surface area are not suitable for shoulder headspacing". So, free ammo and it headspaces on the mouth. I would not even consider this conversion with a double action revolver, but the Blackhawk has mechanical advantages over a double action in both ejection of spent cartridges and cylinder rotation. I am not trying to hotrod it like the B and D round. I also don't even expect to get as much as a 357 mag. Also around here in the last ammo drought 357 Sig could be found. (I can fully recommend a Wolf 357 Sig conversion barrel for a Glock 35). I am just the kinda guy that likes options.

 

[NikA]

The "advantages" of bottlenecked pistol cartridges are generally considered to be feeding reliability (think of the bullet as a smaller guide for the rest of the cartridge) and shorter OAL (for smaller guns that fit smaller hands). You lose both of these in a re-chambered revolver, since your feeding reliability isn't an issue (and you don't have the rim to extract on) and the cylinder is whatever length the cartridge it was originally designed to accommodate required.

I would say the main reason for the "limited popularity" of other bottlenecked pistol cartridges is the lack of major manufacturer support. The two "successes" I can think of are .357 Sig and 7.62x25mm Tokarev, both supported by enormous manufacturing concerns. The "boutique" ones, like .25/.32 NAA or .400 Corbon, tend to be loaded by only a few manufacturers at best. Performance-wise, there are other ways to achieve the same objective with currently available cartridges.

 

[Chief 101]

The Blackhawk should handle the pressures, the bottleneck cartridge will likely set back enough to lock your revolver's cylinder, and, with a lot of freebore in the cylinder accuracy may be subpar...talk to a qualified pistolsmith about this...he may have actual experience here...my experience is with the B&D round and I locked the cylinder up a few time looking for good loads...goodluck with your endeaver