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Discussion Starter · #1 ·
The mystery of SAAMI and CIP max pressure specifications for 32 S&W and 32 S&W Long

I was reviewing the SAAMI and CIP pressure standards for the 32 S&W and 32 S&W long and came across some interesting information:

SAAMI CIP
MAP (psi) Pmax (bar/psi)

32 S&W 17,000 900 / 13,050

32 S&W Long 15,000 1000 / 14504

32 S&W Long WC -na- 1550 / 22481

Surprisingly, the SAAMI MAP (maximum average pressure) for the 32 S&W is 2,000 psi higher than the 32 S&W Long. Because of the age and weakness of most 32 S&W pistols, it is unlikely that any commercial 32 S&W ammunition is loaded to the SAAMI specification. Frankly, I am at a loss to figure out why the 32 S&W MAP would be higher than the 32 S&W Long MAP. The CIP Pmax specifications are more in keeping with what I would expect for these two cartridges. Since it is generally accepted that the 32 S&W can be safely fired in a 32 S&W Long revolver, it would seem reasonable that the 32 S&W Long cartridge should be able to operate at the same MAP as the 32 S&W. That being the case, the extra 2,000 psi makes a significant difference in the energy of a full-house loading for the 32 S&W Long. Here are some theoretical calculations made in Quickload (being theoretical, powder weights can be specified to the 1/100 of a grain to more closely match the max pressure specification):

32 S&W Long

100 gr RNFP / 3.96 gr Herco / 1.246 OAL
14459 psi / 937 fps / 195 ft-lb / 90.3% Burn / 68.1% Fill

100 gr RNFP / 4.28 gr Herco / 1.246 OAL
16976 psi / 1003 fps / 223 ft-lb / 93.1% Burn / 73.4% Fill

We find that an extra 28 ft-lb (+14.4%) of muzzle energy is possible using the higher 32 S&W SAAMI pressure specification.

The CIP specifications are interesting as well. Unlike SAAMI, CIP includes a Pmax specification for a wadcutter round. This pressure limit is much higher than specified in SAAMI or CIP for a standard round. Again, I am not sure about the reasoning for this. Possibly, it compensates for the very rapid pressure drop as the deeply seated wadcutter projectile moves out of the casing and into the cylinder. It could also be that this initial high pressure occurs only in the thicker web of the case and not in the thin area near the mouth. If this level of pressure was acceptable for a non-wadcutter round the increased energy would be very significant:

100 gr RNFP / 4.87 gr Herco / 1.246 OAL
22335 psi / 1119 fps / 278 ft-lb / 97.0% Burn / 83.7% Fill

This level of energy would turn the normally mellow 23 S&W Long into a serious contender for SD use. I am not sure if many pistols chambered for the 32 S&W Long could safely handle this pressure, but it does have some interesting implications.

I solicit the thoughts and ideas from anyone who can help make sense of these varying and sometimes contradicting specifications.

Marshall
 

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My data was obtained by downloading the PDF here: SAAMI

Click on ANSI/SAAMI Standards for Centerfire pistol and revolver. And, Velocity and Pressure Data Centerfire Pistol and Revolver.

On the CUP scale they list them as the same. FWIW. Can't explain the other part, save it was an arbitrary difference to obtain the listed velocities from the shorter cartridge.

A lot of 32 Longs are in the small I frame Smiths ( I have one myself) and/or are in revolvers with non heat treated cylinders. My I frame, while late enough to have the heat treated cylinder, has smaller sized parts containing and absorbing the pressures of the round, so it's best for longevity to stay well below 900 fps (4.25" barrel) and nowhere near the loads you mentioned.

In fact,the Herco load you propose is rather too stiff for sustained use in the more common J frame 32 revolvers. Here you're duplicating or exceeding 32 H and R ballistics out of a shorter case, with pressures exceeding 38 Special Plus P. Since a lot of the J frames have softer cylinders and frames measuring on the Rockwell "B" rather than the "C" scale (the later production J frames were and are so produced but likely none were made in .32) it is probable that such loads should be occasionally rather than frequently fired in the J frames, as Smith hasn't produced a J frame in 32 in awhile.

Knocking 100 feet per second off your proposed load using Herco for the larger J frame wouldn't hurt penetration with a flatnosed bullet as it will be already ample, and the load won't be so hard on the gun. Here I'm presuming a reasonable barrel length to obtain said velocity.....as in, no snubbies! CIP specs may? have to do with 32 Long use in autoloading target pistols which may be designed for deeply seated bullets and reduced case capacity.

Nowhere near that pressure level is advisable with many of the older 32's, even the high quality ones. When the Herco load you propose mimics 38 Special +P energies out of a smaller diameter, shorter case and houses such pressures in a smaller frame revolver of more questionable frame hardness......there's a great, big fat hint not to go there.

Since good small frame 38's abound that shoot and are rated for Plus P due to superior metal hardness......perhaps it's a much smarter idea to save the older (and that's nearly all of them) 32 revolvers for milder loads only. A 98-100 grain SWC at a mere 900 to 950 fps certainly won't underpenetrate on any human target.
 

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I don't have the knowledge you gentlemen have but I do have a 1952 H&R .32 long revolver. It does fine with factory loads and I would not try anything stronger in it. If I actually felt the need to experiment then I would lean toward my 327 Fed Magnum Taurus. It is presumably built to handle 45000 PSI. Actually I guess it just makes more sense for me to use the longer and stronger cases anyway.
 

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I'm liking what 35Remmie had to say on the subject. 32 and 32Long are from several generations ago, design and metalurgically speaking. The 1000fps round you're looking for already exists as the 32 H&R, which was chambered in the overbuilt Ruger SP-101 and Single Six along with the Marlin 1894 in, addition to some H&R's and others.

For the higher end loads, the 327 Fed Mag exists, which does equal or exceed 38spl loadings and IS designed for self defense use.

While reloaders have more flexibility than the general shooting community in making and customizing cartridges, it distinctly sounds like you're re-inventing the wheel....using non-appropriate parts. Personally I love the 32 in general and have been looking for a reasonable S&W 30 or 31 for some time. But to use it for what it's perfect for. Accurately punching paper and cans, painlessly teaching others to shoot and small game hunting.

Since the only 32 S&W/Longs still produced are high end Bullseye and Olympic competition guns, you'd have to be looking at 50+ year old wheelguns which just weren't designed/proofed to be fed a steady diet of mini-magnums. IMHO, you would be far better off starting with a 32H&R or 327FedMag firearm and THEN playing with the loads you're looking for.
 

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Discussion Starter · #5 ·
@35 Remington,

You hit the nail on the head with your explanation on the .32 wadcutter spec:

" CIP specs may? have to do with 32 Long use in autoloading target pistols which may be designed for deeply seated bullets and reduced case capacity."

I just ran across this information today:

"Reloading for Handgunners" by Patrick Sweeney, Krause Publications, 2011, p141

"Unlike the .38 Special, where the wadcutter load is usually lower pressure for reduced recoil, the .32 Long wadcutter is often loaded to a higher pressure than the standard so the ammunition will reliably cycle the pistols chambered for it. That's right, pistols. In much International target competition, "centerfire" means .32, and there you'll find ferociously expensive target pistols in .32 Long Wadcutter. So don't pick up a box of .32 wadcutters expecting a softer load for plinking."

So, it looks like the wadcutters are being loaded to the higher CIP pressure (i.e. 22481 psi) for these high end target pistols. It would seem prudent that these wadcutters should not be used in regular M30/31 and earlier revolvers. Personally, I have a very robust Ruger SP101 in 327 Fed Mag that I use for testing my "special" 32 S&W Long/32 H&R Mag loads so I am not too concerned about the higher pressure of the wadcutter rounds. However, knowing what I know now, I think I will avoid the use of commercial wadcutters in my prized post war pre-model 30 S&W .32 hand ejector that was made in 1949.
 
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