32 S&W (short) w/Win244

[HumptyDumpty]

My limited chronograph data:

1.2gr Red Dot, 73 Grain ACME Bullet- 498, 532, 451, 515, 494 FPS

Random assortment of vintage BP rounds (likely featuring 80-90 projectiles): 653, 620, 631 FPS

One BP round of my own creation, with the aforementioned ACME bullet: 725 FPS

All rounds were fired through a solid-framed H&R 733, with a 2 1/2" barrel. Just for those who might be interested, 2.7 grains of Red Dot in a 32 S&W Long case, from the same revolver, propels a 100gr SWC to nearly 900 fps. I've had alot of fun playing around with the 32 S&W short and Long. I did get ahold of some 71 grain, 32 cal HP's, and made a few 32 S&W short "Defensive +P" rounds. I seem to have misplaced my notes, but it was over 2 grains of Red Dot. Fired from an SP101 for safetie's sake, It had the same recoil and muzzle blast as a stout 32 long. Unfortunately I failed to get a good chronograph reading.

[TheAbe]

And this is exactly the type of conversation I had hoped would occur here. Can’t wait to start threads on a few other cartridge loadings.

In the meantime, my seating depth for modeling purposes is ~.193”, with an OAL of .874” for the brass I’m using. As for the discrepancies in the model vs experimental data, there could be some issue modeling such a small case due to the internal case geometry being rounded at the base instead of perfectly flat. With such a small volume this might actually make a difference. Also, depending on the age of the rounds tested, could there be some increased pressures due to changes in the chemical composition of the powder over time? I’ve heard that, for example, much of the 8mm Mauser surplus rounds from Turkey have undergone a bit of decomposition over time, and as a result are significantly hotter than they were when they were made. If we’re talking decades, those tested 32 S&W rounds could have similarly changed. The supposed max pressure for 32 S&W is only 12,000 psi right?

[HumptyDumpty]

And this is exactly the type of conversation I had hoped would occur here. Can’t wait to start threads on a few other cartridge loadings.

In the meantime, my seating depth for modeling purposes is ~.193”, with an OAL of .874” for the brass I’m using. As for the discrepancies in the model vs experimental data, there could be some issue modeling such a small case due to the internal case geometry being rounded at the base instead of perfectly flat. With such a small volume this might actually make a difference. Also, depending on the age of the rounds tested, could there be some increased pressures due to changes in the chemical composition of the powder over time? I’ve heard that, for example, much of the 8mm Mauser surplus rounds from Turkey have undergone a bit of decomposition over time, and as a result are significantly hotter than they were when they were made. If we’re talking decades, those tested 32 S&W rounds could have similarly changed. The supposed max pressure for 32 S&W is only 12,000 psi right?

I'm not sure that this would apply in the case of black powder, though I seem to recall reading somewhere that, if it gets wet and subsequently dried-out, it can become a bit more powerful. I have no idea if that is true or not. I've yet to encounter any smokeless powder that had become noticeably more spicy with age, though I have definitely heard some stories. And yes, the pressure limit is very low.

[Larry Gibson]

uscra112

Expansion ratio? I'll have to think on that idea. I don't see that QL has any factor accounting specifically for volume of gas evolved from the deflagration. Boyles' Law will apply, however, so maybe it isn't necessary.

It is most often thought barrel length has the greatest effect on velocity. However, it is actually the expansion ratio which has the greatest effect. Expansion ratio is the ratio of the volume of the bore from the base of the bullet to the muzzle compared to the volume of the case to the base of the bullet. An expansion ratio of 10 to 1 simply means the bore is 10 times that of the case volume. With such an expansion ratio the bore volume doubles in 1/10 the length of the bore from the base of the bullet to the muzzle. To quote from "Firearms Encyclopedia, Harper & Row"; "a 38 SPL revolver with a 6" barrel actually has a greater expansion ratio than many rifles with 20" barrels."

You were firing a very short round in a much longer chamber. How much gas was getting past the bullet during that long jump to the leade?

Perhaps some, but given the ES of 32 fps for the test (7 shots) it appears to have been consistent.

Lastly, and not wishing to give offense, as a superannuated automotive process gaging guy I have to wonder about how well calibrated your strain gage system is. What is the protocol? Does it correlate well with the copper-crusher lab instruments? Does it have a linearity or bias issue when used for such low pressures? Information I would stand a chance of knowing had I ever had one to work with, but of course I haven't.

The gauges are calibrated by the manufacturer and a calibration factor is given. That calibration factor is entered into the program. If a strain gauge is replaced the new gauge will have a new calibration factor which is entered into the program before use. The use of "reference ammunition" is then used before any testing of loads is done. In this case the "reference ammunition" is Federal factory ammunition of a known psi. The 18,200 psi the Federal reference ammunition tested at the beginning of the above tests is only 100 psi different from the stated pressure of the ammunition. That is well within expected test to test variation.

FYI, piezo transducers as used with modern pressure guns are actually strain gauges. Many manufacturers additionally use strain gages on their test firearms in lieu of or in addition to piezo transducers.

The "protocols" I follow are SAAMI protocols as out lined in their manuals.

[Larry Gibson]

[QUOTE=TheAbe;5492709].......... Also, depending on the age of the rounds tested, could there be some increased pressures due to changes in the chemical composition of the powder over time? I’ve heard that, for example, much of the 8mm Mauser surplus rounds from Turkey have undergone a bit of decomposition over time, and as a result are significantly hotter than they were when they were made.

Having shot up a lot of that Turk 8mm ammo with headstamps dated in the mid '30s up through the mid '40s and still having several thousands of it to shoot I have pressure tested a lot of it. I have found no evidence of decomposing powder. What I have found is the cases were apparently not annealed correctly and the case necks, if not already slpit can easily be split. In other words, the cases are brittle which also causes difficult extraction. As to being loaded "hotter" they are loaded to European, specifically German, standards of velocity and pressure which, of course, is "hotter" than US standards. However, that is not in the context of "hotter" as meaning excessive pressures.

If we’re talking decades, those tested 32 S&W rounds could have similarly changed.

Before testing any ammunition other than my own loads I always pull down a few rounds and inspect. No indication of powder decomposition was found. This is also done to enter the load data into the program.

The supposed max pressure for 32 S&W is only 12,000 psi right?

Wrong. The SAAMI MAP (Maximum Average Pressure) for the 32 S&W cartridge is 17,000 psi. The MPSM (Maximum Probable Sample Mean) is 18,300 psi. Interesting to note is the MAP for the 32 S&WL is 15,000 psi and the MPSM is 16,200. That was the point of my post showing actual measured pressures and pointing out the old myth of "it is safe to shoot 32 S&W in old 32 S&WL revolvers because the pressure is less with the 32 S&W". That is not the case as we see from the actual measured pressures.

[uscra112]

As of midnight I'm farther from reconciling the QL models to Larry's data than I was before.

But I can confirm that the SAAMI MAP is 17,000. and that the 12,000 figure quoted in that old Speer manual is the CUP (copper-crusher) value. (Wiki by the way, as always, is misleading. Quotes the CUP value without identifying it as such.)

17,000 seems awfully high for these old guns.

I've long used a value of 14,000 psi for black powder. Obviously variable depending on granulation. Am I close?

@theAbe - would you take a few of your fired cases and very carefully measure the water capacity in grains weight? I want to confirm (or debunk) the volume as found in the QL database. Also check that .193 seating depth. That depth leaves no room for the typical 231 or Bullseye powder charges commonly quoted.

Edit: .874" would be a case length closer to S&W Long. Nominal length for the short is .605". Which one are you loading?

Another semi-relevant datum I've turned up: A 1904 Stevens catalog states that the .32 Short Colt was loaded with 9 grains of black, but that cartridge is slightly smaller in diameter and uses a heeled bullet that seats only .125 into the case.

All in all, if S&W short is being loaded hotter than the Long version, it's certainly a caution to owners of these old guns not to shoot factory ammo in them. Given the number of old .32 Short revolvers rescued from sock drawers that their ammo might be used in, it's either irresponsible on the ammo-makers' part, or those guns are stronger than we've been led to believe all these years.

[TheAbe]

Thank you Larry for clarifying, and clearing up my confusion about the maximum pressure of the cartridge. That makes a lot more sense now. Also gives me a bit more respect for the cartridge. As for the revolvers, has anyone performed mechanical tests on the various parts of some of the old “smokeless safe” revolvers to see just how strong or weak they really are? It would be a pain, and one would need a strain tester or the like... sorry, my background is in materials engineering, and now I’m thinking along that path. It would seem the weak points would be the cylinder and possibly the top latch and the pin that holds the barrel assembly to the frame. The latch and pin would take a reduced force though since much of the pressure is being expended on the bullet forward vs pushing the barrel forward.

As for the cartridge measurements, does the cartridge need to be fired or would an unfired empty suffice? And you want the full case capacity right, not including the bullet-seated part? I will re-measure: empty case is 0.600”, bullet is 0.467”, OAL is 0.870”. Seating depth is about right. Case depth is 0.420”. The discrepancy is that I’m not actually using Win 231, but Win 244. 231 has a VMD of .0931 cc/gr whereas 244 has a VMD of .0789 cc/gr (using the Lee term here). 244 takes up less space in the case. 2gr of 231 would be .1862 cc 2.0gr 244 would be .1578 cc. Sounds like I should back out that seating depth a bit otherwise I might go overboard with pressure, even with a 2.0 gr load....or am I completely off-base there?

Based on my micrometer measurements (I’ll measure with water later) the ID of the cases is .309” and the case capacity after the bullet is seated to the depth I have it should be about .279cc with a total capacity of an empty case around .516 cc.

[uscra112]

Fired only because it'll have the spent primer in place to keep the water in.

[TheAbe]

Oh ok. As I do not have any fired yet, I will instead prime an intact, spent primer into one of my cases (or a few of them) for that purpose.

[trapper9260]

Hope Outpost post on here he know also about the 32 , Larry knows what he doing and help me in the past also. It is interesting for the test Larry comes up with. He is a big help. The Abe just ask what you need help with and someone is willing to help you . I shoot 32 S&W in my 327 s also 32ACP it .

[TheAbe]

The more the merrier! And yes, I shall, as I have lots of questions that the answers I have not seen posted or printed. Going to see if I can do the water test now, and will be back with results shortly.

[TheAbe]

Ok, first time doing this, and of course I pick one of the smaller cartridges to attempt. Surface tension meant that the water in these cases made a very nice dome at the top, which could throw off the results a bit. I took two measurements for each: 1) the dome just visible over the mouth of the case; and 2) where the case was full and the dome rising out quite a bit. If I were to pick, I’d use the former measurement, but here are the averages of five cases for both measurement types: 7.4gr and 7.9gr. The former translates to about .480g or .480cc. The latter translates to .512g or .512cc. Not too far off from my micrometer measurement, with the difference explained by the curvature of the case base.

[racepres]

[QUOTE=Larry Gibson;5492731]

.......... Also, depending on the age of the rounds tested, could there be some increased pressures due to changes in the chemical composition of the powder over time? I’ve heard that, for example, much of the 8mm Mauser surplus rounds from Turkey have undergone a bit of decomposition over time, and as a result are significantly hotter than they were when they were made.

Having shot up a lot of that Turk 8mm ammo with headstamps dated in the mid '30s up through the mid '40s and still having several thousands of it to shoot I have pressure tested a lot of it. I have found no evidence of decomposing powder. What I have found is the cases were apparently not annealed correctly and the case necks, if not already slpit can easily be split. In other words, the cases are brittle which also causes difficult extraction. As to being loaded "hotter" they are loaded to European, specifically German, standards of velocity and pressure which, of course, is "hotter" than US standards. However, that is not in the context of "hotter" as meaning excessive pressures.

If we’re talking decades, those tested 32 S&W rounds could have similarly changed.

Before testing any ammunition other than my own loads I always pull down a few rounds and inspect. No indication of powder decomposition was found. This is also done to enter the load data into the program.

The supposed max pressure for 32 S&W is only 12,000 psi right?

Wrong. The SAAMI MAP (Maximum Average Pressure) for the 32 S&W cartridge is 17,000 psi. The MPSM (Maximum Probable Sample Mean) is 18,300 psi. Interesting to note is the MAP for the 32 S&WL is 15,000 psi and the MPSM is 16,200. That was the point of my post showing actual measured pressures and pointing out the old myth of "it is safe to shoot 32 S&W in old 32 S&WL revolvers because the pressure is less with the 32 S&W". That is not the case as we see from the actual measured pressures.

Lucky me.. to have "learned" about the 8X57 JS via Turk and European ammo... Not US mfg... a quick google search reveals Much about that.
Now the Darn little 32's I would be willing to bet good hard earned $ that. originally, the 32S&W Long was "hotter" than 32S&W.. especially knowing they were originally (32S&W certainly) black powder Ctgs... now, the 32 acp... hotter due to being Newer, and no existing firearms restrictions. Above all that, common sense Should tell us that a Longer Case is Not wise...ie 32ACP in a 32S&W chamber..
Having typed all that Mumbo Jumbo... I feel secure in choosing 32S&W "pressures" in my 32S&W Long, solid Frame, Revolver.
But... No reason to go to 32ACP "pressures" even in the long, since some kind soul invented the 32H&R Mag..
Must go back to the Break top revolvers tho.. I do Not believe that the majority of them were designed for much more "Use" than self defense...and therefor, the Latch should live thru that encounter... this was Not a target/plinking piece, that I can figger...
so... yes a Chronograph, 78 gr lead boolits, and about 500-600 FPS.. should, theoretically ... be "kind" to that firearm..

Note... All absolutely Supposition on my behalf... certainly Not Scientific, nor even perhaps Verifiable... Just my $0.02

[uscra112]

@TheAbe - should have mentioned it - a drop or two of liquid dish detergent in a cup of water will reduce that meniscus.

[uscra112]

@TheAbe - should have mentioned it - a drop or two of liquid dish detergent in a cup of water will reduce that meniscus problem.

Your 7.4 grains is 30% more than what's in the QL database. Might just be a difference in brass mfgr. The tiny .32 Short case is incredibly sensitive to this, and also to seating depth. Plugging in your 7.4 grains, and a bullet of 78 grains seated .193 deep, I get reasonable numbers now for pressure and MV using 1.5 grains of 231. (I'm using my own I.J.'s barrel length of 4.0 inches, muzzle to recoil shield.)

Now we really need some chrono data on that load. Due to my wretched back pain troubles I'm not able to do it just now. (Can't even walk as far as the backyard range.) I've refined the QL model about as much as I can at this distance. Still can't get anywhere near Larry's MV numbers.

[TheAbe]

With the meniscus removed I’m getting an average of 7.6gr H2O. So yes, I’m curious about what QL would say about that load as well as a load of 2.2gr everything else being equal.

On the subject of IJ top-breaks, I haven’t fired these yet but both my .32 and .22 appear to have a cylinder gap of .014 inches, is that a problem? What does your IJ’s gap measure? Obviously I’d be keeping well aware of the location of my fingers in any case.

[hoodat]

I'll weigh in with my experience with this little cartridge, and the little top-break pea shooter pistols of that vintage.

I was always a big Bullseye powder fan, but when it came to throwing these tiny charges of less than two grains, I found that my RCBS Uniflow measure was more accurate and less problematic with HP38/WW231 than with my old Bullseye standby. The HP38 seems to be slicker grains (maybe graphite) and doesn't smudge and stick like the Bullseye does in the tiny gap necessary for only a grain or so of powder. I would use my Lil Dandy, but don't have the bushing required for the tiny charge.

I concur on the 1.5 gr. charge of HP38. and am using a 77gr. Laser Cast round nose seated at .880". (as per Lee instructions)

Of the various top-breaks I've had, I judge the Smith and Wessons to be the highest quality, and most durable of the various brands. I've also got a theory concerning how to keep these little pistols in decent shape. The tension of the top latch and hinge screws should be maintained so neither becomes loose, allowing the sloppy fit that is noticeable in many of these older guns. I believe those two mounting points work together for the strength of the system and I've seen some that were made dramatically better simply by tightening those screws.

This blued model (S&W) is 100 % pristine mechanically, and probably 90% cosmetically, and a real hoot to shoot. jd

Attachment 307338
Attachment 307339

[uscra112]

Just eyeballing it, I'd say the gap in mine is at least .015, and the end shake is close to that, too. These weren't target guns. Meant as "belly-guns", which one friend claims to mean that you stick the muzzle into your opponent's (or victim's) belly before pulling the trigger. Before modern medicine, one round into the intestines meant a slow, agonizing death from peritonitis, as happened to President Garfield. Pretty effective deterrent.

[uscra112]

1.5 grains of Bullseye, HP38, or W231. The model can hardly tell the difference. Of Unique go to 1.8 grains. Calculated pressure ~9,000 psi, (CIP method). MV in the 650 fps area from 4" barrel. Actual MV value certainly less due to the large cylinder gap. Needs verification by Chrony.

[hoodat]

The cylinder gap on the one pictured above is .009", and as mentioned is pretty much good as it gets mechanically. The internals on these Smiths are beautifully fitted and finished, -- like a Swiss watch. Amazing to consider that they sold for around 7 to eleven dollars.

Attachment 307342