.327 conversion???

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mjackson

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I am thinking of converting a .32 Long revolver to .327 Federal or even .32 H&R magnum in order to gain more performance from the same revolver. I have read many times about shooting smaller cartridges in cylinders with longer throats and how that might cause an extraction problem because of carbon build up. I want to be able to shoot .32 Long, .32 HR and .327 from the same revolver with no extraction problems, so my question is: How can I determine what is considered a tight chamber in .32?
 
What Mr.trooper said. I don't think theres been any modern revolvers chambered in .32 long for a long time. Pressure's from a .327 magnum would probably destroy an old gun.
 
FWIW - Just get a .327 and you can shoot all the .32 rounds. That is one of the considerations that led to the purchase of the Taurus M327 I have on the way.
 
Most guns that were factory chambered in 32 S&W Long can't withstand the pressure of 327 Federal. I can't think of even one 32 Long revolver that I would ever consider doing this to. 327 Federal runs at right around 45,000 PSI as I recall, versus 15,000 psi for 32 Long or 21,000 psi for 32 H&R Mag.

This has Bad Idea written all over it.
 
+ 1,000!

No .32 S&W firearm ever made is strong enough to withstand .327 Federal pressure.

No manufacture chambers .327 Federal in anything that wasn't designed for at least the .357 Magnum in the first place.

rc
 
Assuming the revolver can handle the pressure, can anyone answer my original question?
Click to expand...

I believe you would have to use a set of plug guages to determine if you have a minimum chamber dimesion. Most factory 32 longs will have looser chambers because of the slightly different cartridges that that have been made since the late 1800s till now. Cases varied a little and the guns were made to chamber them all.

If you want a tight chambered 32 long it would have to be a custom gun and I bet that any that were made are safely hidden away in someones collection. Thats if any were made in the first place.

Chamber size has nothing to do with fouling anyway. A shorter case will always foul a longer chamber. If you don't want extraction issues all you have to do is clean the gun. I hope that answers your question.
 
You will have to google or get a copy of barnes cartridges of the world and do some research. Standard case diminsions are made to work with all cases. A match case will be tighter and that can be almost anything.

Since the 32 long was originally loaded with around a .314 lead bullet and most jacketed bullets are .312 or smaller then you see the problem with calling any chamber a minimum chamber.
 
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Code: 
Case type       Rimmed, straight-walled                    
Primer type     Small Pistol

                .327 Magnum        .32 H&R Magnum      ,32 S&W Long        .32 S&W
                2007               1982                 1896                1878
Parent case     .32 H&R Magnum     .32 S&W Long        .32 S&W             greatgreatgranma
Bullet diameter .312 in (7.9 mm)   .312 in (7.9 mm)    .312 in (7.9 mm)    .312 in (7.9 mm)                  
Neck diameter   .337 in (8.6 mm)   .337 in (8.6 mm)    .337 in (8.6 mm)    .334 in (8.5 mm)
Base diameter   .337 in (8.6 mm)   .337 in (8.6 mm)    .337 in (8.6 mm)    .335 in (8.5 mm)
Rim diameter    .375 in (9.5 mm)   .375 in (9.5 mm)    .375 in (9.5 mm)    .375 in (9.5 mm)
Rim thickness   .055 in (1.4 mm)   .055 in (1.4 mm)    .055 in (1.4 mm)    .045 in (1.1 mm)
Case length     1.20 in (30 mm)    1.075 in (27.3 mm)  .920 in (23.4 mm)   .61 in (15 mm)  
Overall length  1.47 in (37 mm)    1.350 in (34.3 mm)  1.280 in (32.5 mmn) .92 in (23 mm)

I think .312 is the typical groove-to-groove barrel diameter, which means lead bullets run .312 to .314 and jacketed bullets run .311 to .312.

.32 S&W was black powder. .32 S&W Long was developed during the smokeless powder era. Both were still relatively low pressure loads and did not require high quality steel, so a lot of older .32 revolvers are questionable. .32 H&R and .327 are recent, which implies guns made for them are made to higher standards than some of the older guns in .32.
 
Some custom gunsmiths have built conversions to the hotter .32 rounds, including wildcats that preceded the .327 Federal. Bowen Classic Arms comes to mind, and I think Alan Harton may have built some. Keep in mind these will NOT be inexpensive options! BCA, for example, has their own cylinders for such endeavors.

Keep in mind that ammo for all of these .32 cartridges is VERY expensive. Hand loading will be necessary to keep things cost-effective. It may be worth a look into hot-rodding the .32 H&R, rather than reaming a cylinder to .327 Federal.

There should be some threads on this at the Single Actions forum frequented by John Taffin, Lee Martin, The Quinn brothers, and other such revolver giants. I will need to go look for the link, as this iPad will not let me do two things at once, without losing what I have just typed.
 
SAAMI minimum chamber diameter for .32 H&R is .3412" measured .200" in front of the breechface. The .32 S&W Long is the same, I do not have specs for the .327 but presume it to be the same or very close since it is intended to accept the other cartridges as subloads.

As said, a minimum (or smaller) chamber would be a custom proposition and would not relieve you of the necessity of cleaning your gun at least when you changed cartridge lengths.
 
Can't think of any .32S&W revolvers that could handle the length or the pressure. However, there are sixguns for which a .327 conversion would not be too costly, relatively speaking. A later model S&W model 16 .32H&R needs only a $150 rechamber but the revolvers are not common. A .32H&R Ruger Single Six needs only a longer cylinder installed. I believe most of those conversions will start around $750, depending on who does the work and what options are included.
 
Just to put some figures (SAAMI) on the table.

Cartridge-----Pressure (cup)
.32 S&W -------- 14,000
.32 S&W Long --- 15,000
.32 H&R Mag ----- 21,000
.327 Federal ----- 45,000.

Yep, 45,000 for the .327; that, folks, is in the .30-'06 class, so no, don't go reaming out that old .32 revolver for .327. Or if you do, don't shoot it anywhere near me; I have grown fond of all my anatomy and hate to lose any of it.

Jim
 
Most .32 Long revolvers I have seen do not have the cylinder length to take a .327 Federal Mag or even .32 H&R Mag.
Click to expand...

That's my thought. Pressure is irrelevant; The cartridges are too long anyway.

The SP-101 is the only revolver I can think of with a long enough cylinder in .32 H&R to ream for .327.
 
I know of a guy who had a S&W 16-4 converted to .327 Federal by the Bowen shop for about $100 with great results. If the Smith can handle it.... Also the Manurhin is a MR 73 Sport not the MR 32 Match, so the cylinder appears just as long as the .357 cylinder. I will find out when I get it.
 
I know of a guy who had a S&W 16-4 converted to .327 Federal by the Bowen shop for about $100 with great results. If the Smith can handle it
Click to expand...

Good point, forgot about the (rare) K32. But they're a K-frame gun, and in .32, there's a lot of meat in that cylinder, and they were built after the K had been magnumized already.

That's also a $1,000 pistol at minimum; Much more economical to buy a new .327 Revolver unless you just happen to have a K32 lying around.
 
The problem there is the availability of new revolvers in the chambering. Rather than the much more suitable Single Six, Ruger gave us a large frame Blackhawk and the GP. The Blackhawk is way too much meat for the chambering and the GP, while a very good sixgun, probably won't satisfy you if what you want is a blued K-frame. That 16-4 could also be fitted with a rebored K-22 barrel if you don't want the full-lug. Not what anyone would consider "economical" but folks usually have custom guns built to spend money, not save it. ;)
 
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