? re: eight shot .327 Blackhawk & conversion to .357

[Otony]

In another thread recently discussing the .327 Blackhawk, mention was made of the feasibility of an eight shot .357 Magnum. Note I am writing about the possibility of building an eight shot .357 Magnum.

I had inquired about just such a .357 custom revolver with Gallagher about ten years back. He had already built an eight shot .32-20, and said the .357 could be done as well.

Fast forward to the intro of the .327 eight shot. I opined that a 'smith should be able to rechamber the existing cylinder to .357 and fit a .357 barrel. A fellow on another forum declared that it couldn't be done, since the chambers wouldn't line up correctly? He wrote the .327 chambers would need to be at a different distance from the centerline of the cylinder than .357 chambers? Sorry, I don't understand that?

Since then I have been trying to wrap my head around that remark. The barrel is in the same place, and cannot move, so according to my limited engineering skills, the centerline of the chambers should always line up with the centerline of the bore, regardless of chamber diameter. Or am I missing something? I think a rechamber and rebarrel should work. Can anyone see any problems with such a conversion?

 

[Nakagawa]

Interesting. I never understood the convertible ability with these revolvers. I understand changing out cylinders but how are they able to shoot different calibers out of the same rifled barrel? An 8 shot .357 would be a great thing in my eyes.

 

[Otony]

Interesting. I never understood the convertible ability with these revolvers. I understand changing out cylinders but how are they able to shoot different calibers out of the same rifled barrel? An 8 shot .357 would be a great thing in my eyes.

You missed this part above: "and fit a .357 barrel".

 

[Ale-8(1)]

Does kinda make ya wonder, doesn't it?

I'll assume that the .327 is built on exactly the same frame size as the .357 versions, and that this means the distance from the base pin to the barrel bore is the same for both guns. This will mean that the same is true for the distance from the base pin to the chambers on the cylinders. I'd further assume that the .327 cylinder is likely the same outside diameter as the .357 cylinder. One would assume from this that the .327 chambers could be reamed to the .357 specs, be properly aligned with the barrel, and have adequate steel on the outside of the chamber bores. A lot of assumptions, for sure.

Seems pretty likely that a .357 barrel could be substituted for the .327 one.

The unknown would be whether the spacing between each pair of chamber holes on an eight-shot cylinder would be acceptable. Might be so close together that the cartridge rims would overlap, or there might not be adequate steel left between the bores. Dunno, but as I see it that's the unknown quantity at this point.

And with all that assuming and speculating, I'd have to mention that this was JMHO.

 

[JimMarch1]

Just in eyeballing the 327 cylinder from pics, I don't think there'd be quite enough "beef" between chambers left.

What I find damned interesting is the possibility of using .308 nylon sabot adapters to shoot .223 rounds from the 327 shells. The .327 bore is actually .312 or so. So hit the .308 sabots with...I dunno, a layer of paint maybe? Enamel? You could maybe make up the difference. The fast handgun twist rate should be perfect for 40gr varmint slugs or something, right?

Freedom Arms already has a wildcat of this sort with the 327Fed as the starting point necked down to .223. They're getting about 2,200fps from a 5" tube. This combination I'm proposing should work in a stock gun, AND would have a lot more case capacity so even with the extra 6gr or so sabot it should be able to beat the FA wildcat?

Worst case, swap the barrel for something actually in .308cal to make this truly work right, use a deepish throat, you should still be able to shoot lead slugs sized .309 or the like (a standard optional sizing for .32cal slugs at Penn Bullets fr'instance).

From a 5.5" barrel, 2,400fps with a 40gr slug stomps the hell out of the FN5.7...

 

[Ale-8(1)]

A .30 Carbine barrel should work.

 

[Otony]

Well, according to Gallagher, an eight shot cylinder does work, and since he builds 'em, I rather imagine there is no "eyeballing" involved.

And the cylinder diameter is larger than than the diameter of an N-frame eight shot .357 as well.

To counter all the guessing, I contacted Alan Harton this afternoon with a request to settle the question. If it can be done, I am doing it!

 

[Jimbo357mag]

Well, according to Gallagher, an eight shot cylinder does work, and since he builds 'em, I rather imagine there is no "eyeballing" involved.

And the cylinder diameter is larger than than the diameter of an N-frame eight shot .357 as well.

To counter all the guessing, I contacted Alan Harton this afternoon with a request to settle the question. If it can be done, I am doing it!

Now that is cool. :shock:

...Jimbo

 

[JimMarch1]

In the version of this thread on the sixgunner forums:

http://singleactions.proboards.com/index.cgi?board=sas&action=display&thread=4929

...we see a possible answer as to what's up: to get eight rounds, S&W altered the frame to move the barrel further out away from the cylinder's axis. This let the rounds ride closer to the rim where there was more beef available between cylinders.

My guess now is that Ruger wasn't prepared to do a special run of frames altered to that degree, so we end up with an eight-shot 327...

Gallagher may have been ready to go there and totally alter the frame dimensions at the front with cutting/welding?

 

[Otony]

I just don't know Jim, but I did get a response from Alan last night. He is going to crunch some numbers and we will see if it is do-able as is.

I believe that response on the other forum is probably accurately describing what was being referred to all those months ago, but it was not made clear originally. If that made sense you are really on track here, btw.

We shall see sooon enough. Oh, and the sarcasm meter wasn't being used when I referred to "eyeballing". To my MarkI eyeball there does not appear to be enough room either!

 

[CraigC]

I have a really hard time believing that S&W moved the bore for one model. Which means everything else has to be offset, including the firing pin. Which amounts to a dedicated frame just for the 8-shot version. I'm not buying it.

IMHO, if the 8-shot Blackhawk can survive the .327 at 45,000psi, then it stands to reason that it can survive a rechamber to .357 with 10,000psi less pressure.

 

[Jimbo357mag]

Consider the thickness between the chambers on a 6 shot .45. Seems like there might be room for eight 357's in the same size cylinder. It won't be difficult to figure out. A person could drill-out a blank disk and do a little measuring.

...Jimbo

 

[Ale-8(1)]

I just measured a cylinder and did a little elementary math.

It appears that the chambers would be so close together that the .357 case rims would interfere with each other.

There wouldn't be much steel remaining between the chamber walls, either.

For what it's worth, my numbers confirm adequate room for the .327 case rims, so I'm confident in my math.

JMHO

 

[Otony]

Dang! Well, I am not disputing your math, but I am curious as to what Alan Harton says.

Now I am wondering how Gallagher claimed he could do it?

 

[Ale-8(1)]

Oh, I'm interested, as well. I'm no gunsmith.

However, if he said he built a .32-20 I believe him because the rim on that round is small enough to clear in adjacent chambers, just as the .327 will.

 

[MAC702]

...Which means everything else has to be offset, including the firing pin...

I don't know what S&W did, but I can tell you that my Kimber 1911 has an offset firing pin. The pin strike on the primer is a full pin diameter off of center. It fires everytime.

All I'm saying is that you COULD move chambers more toward the outer edge of the cylinder by enough to make a difference and still have reliable ignition without altering the frame or even modifying the existing firing pin.

You may not be able to move it as much as my 1911's, being a small primer instead of large, but I see no reason for a perfectly centered firing pin, and you would probably be able to pull it off.

 

[Ale-8(1)]

You can't move the chambers without moving the barrel and that's a frame revision. Therein lies the problem.

Can it possibly be done? Almost certainly, but I'd hate to think how much it would cost.

Given enough money, anything is possible.

For what it's worth, S&W's eight-shot .357 is on their large "N" frame.

 

[edlmann]

You can't move the chambers without moving the barrel and that's a frame revision. Therein lies the problem.
Can it possibly be done? Almost certainly, but I'd hate to think how much it would cost.
Given enough money, anything is possible.
For what it's worth, S&W's eight-shot .357 is on their large "N" frame.

IIRC, they also have a 7-shot version of the 686 on the L frame.

 

[Ale-8(1)]

Yep.

And the math reveals there should be adequate rim clearance for a seven-shot .357 in the Blackhawk.

 

[KWYJIBO]

.

IIRC, they also have a 7-shot version of the 686 on the L frame.

That's correct. They call it the 686+