380 ACP Lyman Data Over the Years

[jdgabbard]

I've been playing with the 380 ACP quite a bit here lately. Internet lore has often claimed that European loadings are quite a bit hotter when compared to those offered US ammunition manufacturers. I'm not going to delve into that topic. I tend to think a lot of cartridges have been neutered over the years. However, what I have seen in my own research of current and older data indicates that pressures suggested by the various manuals have significantly lowered the bar for this cartridge in particular. If you look to the SAAMI specifcations the .380 ACP it has a max PSI of 21,500. Yet, when you look at the Lyman manual as an example, it seems that most loadings max charge tops out at 16,000 PSI. (btw, yes I am familiar with the differences between PSI and CUP, I'm using data with the same units of measurement). And it would seem this trend actually happened sometime back in the 80s or 90s.

When looking at Data from the 45th Lyman Reloading Handbook, it lists the 358242 92gr variant with charges of Bullseye at 2.4-2.9gr (869-995fps), and Unique at 3.9-4.5gr (952-1155fps). That Unique loading sounds pretty stiff in comparison to today's loadings, and does sound much closer to stories about some of the older 380 ACP loadings. However, if we flip forward to the Lyman 47th Reloading Handbook from 1992 (I do not have a copy of the 46th to reference) we see that the Bullseye load has now been increased a hair, 2.4gr-3.0gr, though with a much lower velocity, 750-915fps. This was probably due to the 3.5" barrel used in the 47th compared to the 5" barrel used in the 45th. But when we look at the loading for Unique, we see a major shift. Now the min/max is 3.1gr-3.7gr for 755-920fps. This new max loading is under the starting load for the 45th manual by a decent margin when considering the capacity of the cartridge.

This seems rather unusual to me. Generally we do expect to see slight variations in data as additional data points are sampled. But a 25% reduction in just the starting load is pretty significant. And it has me wondering why. Surely there was not that large of a difference in the quality of arms being manufactured between 1970 and 1992. At least not in the sense that the newer arms were of lesser quality (except for maybe some of the cheap pistols on the market). And I think 1992 is even before the Alliant takeover of Hercules' powder, which I think happened around 1995. So we're not talking about any supposed change in powder formulation.

Does anyone have a bead on this? Do we have a definitive reason for the reduction, or just speculation that the Unique charge was just way too hot. Curiously, it does seem to be a closer comparison to the Buffalo Bore loadings, particularly the 90gr JHP at 1200fps and the 100gr Cast at 1150fps. My best guess is there may have been concerns about older guns. But, when I plug the numbers into Gordan's Reloading Tool, I only get 17,444 PSI with the max 4.5gr load. Which leads me to believe that this load may possibly still be safe. Lyman just reduced the loading for some unknown reason. Although, admittedly GRT is still not the most accurate tool, and maybe someone who has QL could check these numbers. But I am assuming the data in GRT is fairly close. And if that is the case, it would appear that many loadings we seem in the manuals for the 380s, as well as commercial offerings, are probably under loaded.

[rintinglen]

That is curious. I looked at my other favorite manual series, Speer, which does not list pressures other than to assert that all loads "do not exceed SAAMI MAP."

I looked in my 10th edition and in my 14th and there I found exactly the opposite. The 88 grain JHP had been replaced by the 90 grain Gold Dot HP, but the charges were increased. The older data for Bullseye was (min-max in grains) 3.0-3.2 while the marginally heavier GDHP shows 3.0-3.4. For Unique, the charges increased to 4.1-4.6 grains from 3.5-3.7. The start load for Unique was over 10% greater than the max load from before! I was assured when I called Speer that they no longer recommend using any data from manuals before No. 11. as they did not switch over to the piezo electric pressure testing until that manual was produced back in the 80's. When I went to my Number 11, I find that the Unique loads for the 88 grain JHP were increased to 3.8-4.0, while the Bullseye loads recommendations remained the same. Looking at the 95 grain FMJ in number 11, (which was not catalogued in No. 10) The Bullseye load was 3.1-3.4, down loaded to 3.0 to 3.3 in the 14th edition. Yet the Unique load is increased from 3.6-3.8 start-max to 3.8-4.2.

Meanwhile, back at Lyman, I looked in My 50th and find for the 356-242 92 grain boolit loads of Bullseye ranging from 2.4 to 3.0 and 3.1 to 3.7 for Unique.

What I need to do is go back and look at other factors such as primers brand and type, brass manufacturer, OAL etc. and see if there is a probable explanation other than a near sighted, hung-over technician misreading data on equipment out of calibration.

For what it is worth, I use the Ranchdog 358-100RF (LEE tl356-95 RF) over 3.2 grains of WW231, loaded to COAL .905.

[jdgabbard]

It seems the data is all over the place from what I have gathered. I need to also go look at my Hornady and Hodgdon manuals and see where they place this type of data - though it probably lacks any cast data. At lease in the Hodgdon manual, which I almost never use as a cross reference.

Personally, I've been using 3.5gr Unique under the 358242, and had been using a load around two and a half grains of red dot (I don't have my notes in front of me). Both of those were accurate loads. And the Unique load seemed a little heavy in my Bersa Thunder. But if I'm a full grain under max that would be good to know. As I mentioned before, GRT indicates that 4.5grs of Unique should still be quite a bit under Max Pressure (17,444psi vs the max of 21,500psi). Though, it's not a CUP measurement, and doesn't have all of the data points. It's possible there are some unusually high pressure spikes in there somewhere. And I'm not certain what type of burn rate verifications they do during development of that tool.

As a side note, this is something I've always really liked about this hobby. Seeing how things change over the years. Heck, even today's data and technologies are vastly different from when I started reloading back in the early 2000s. Heck, even from the early 2010s.... Maybe one of these days I'll have enough liquid assets to afford some fancy pressure testing equipment so I can get to the bottom of all this stuff...

[Larry Gibson]

CUP testing via special barrels in a Universal Receiver is expensive, slow and tedious. Much of the data in older manuals was derived the same way they advised working up a load; basically to watch for pressure signs then back off. However, in the '80s two thing occurred; one was, after several legal litigations, it became obvious that SAAMI, even though a "volunteer" organization, was considered to be the "standard" with regards to specifications and pressures of cartridges. The other was the use of transducers to measure pressures. The use of transducers and strain gauges (actually a form of transducers) long with their ease of use and relatively inexpensive computer software allowed much better testing of cartridge pressures.

Thus, with a better more precise means of testing and adherence to SAAMI Standards, most data in newer manuals will differ from older data. Doesn't mean that older data was necessarily wrong. It just means that older data didn't fall within current standards.

[jdgabbard]

CUP testing via special barrels in a Universal Receiver is expensive, slow and tedious. Much of the data in older manuals was derived the same way they advised working up a load; basically to watch for pressure signs then back off. However, in the '80s two thing occurred; one was, after several legal litigations, it became obvious that SAAMI, even though a "volunteer" organization, was considered to be the "standard" with regards to specifications and pressures of cartridges. The other was the use of transducers to measure pressures. The use of transducers and strain gauges (actually a form of transducers) long with their ease of use and relatively inexpensive computer software allowed much better testing of cartridge pressures.

Thus, with a better more precise means of testing and adherence to SAAMI Standards, most data in newer manuals will differ from older data. Doesn't mean that older data was necessarily wrong. It just means that older data didn't fall within current standards.

Larry, thanks for chiming in. Your input is always welcome.

How would describe the inconsistencies with modern loads pressure tests then? If you look at the most current Lyman manual, doesn't use the CUP measurement, the Max loads are well under the SAAMI specification of 21,500. I don't have it in front of me, but it was like 16,000 PSI. Obviously they probably don't want people pushing the envelope. As I mentioned earlier, I do not have any means of pressure testing, but I do use GRT. It estimates that even the 4.5gr Unique load is down around 17,500 PSI. Obviously I wouldn't rely solely on what an enthusiast written software program tells me alone. I'm just pointing out that adherence to SAAMI is one thing. But the new data doesn't even appear to do that. It was as if they just set a velocity threshold for the caliber and left it at that, rather than even considering the SAAMI specifications for the cartridge.

[Larry Gibson]

"How would [you] describe the inconsistencies with modern loads pressure tests then?"

It's only a guess but given the wide variation in groove diameters of the myriad of 380 ACP handguns out there as mentioned in the comments may have a great deal to do with it. Also, Lyman has really no control over the seating depth that reloaders use. In that small case a different design of bullet which may seat deeper can cause very large pressure increases. There are also a few loads that do approach the 21,500 SAAMI MAP for the 380 ACP.

[elk hunter]

The 380 like the 9MM Luger has and is made all around the world. Each manufacturer of the firearm and of the ammunition follows their own countries standards. There is variation in the firearms and the ammunition. Having loaded many thousands of rounds of both calibers I can attest to variation of the basic dimensions of the cases for both. Small variations in the thickness hence the capacity of such a small case can have significant influence on the pressure. The smaller the case and the faster the powder the greater the influence a small variation can have. A small variation, say .5 grain, in a small case is a larger percentage of the total than the same amount in a larger case. As pointed out by Larry Gibson seating depth is another variation that can change pressures dramatically. Even changing the brand or type of primer can make a decided difference.

Just my $0.02 worth and maybe not even worth that.

[WRideout]

I am running into the same kind of variation with 9mm Para. I shoot the Lyman 356402 truncated cone in my nines. I had been using 4.3 gr of Promo (Red Dot equivalent) as a standard load. According to the Lyman Cast bullet Handbook #3 that is a moderate charge; 4.5 gr is max. Lyman #4 does not list a Red Dot load for that bullet. Just yesterday I was browsing my Speer #10 Reloading Manual, and found that for their 125 gr swaged lead bullet, a max charge of Red Dot was 3.6 gr, with a velocity of 1004 fps.

Now I understand that these are different bullets, with different seating depths, etc. But I do find it hard to believe that a boolit that weighs around four grains less can handle a significantly greater powder charge without difficulty, all other things being equal. BTW I shoot my pet load regularly in both my nines without any sign of excessive pressure.

I don't believe that the load data, as given in the manuals was unsafe at the time of publication; their lawyers would never have allowed them to be published if it were. I am guessing that there are arbitrary safety factors that go into the interpretation of the data, which can change over time, and with different manufacturers.

Wayne

[Charlie Horse]

Good thread. I've been doing some work with the 380. Some of those Bullseye loads look a tad light to me. But I'm shooting out of a Glock and it would seem to be a bit more stout than the new, pocket 380's out there.

[jdgabbard]

I am running into the same kind of variation with 9mm Para. I shoot the Lyman 356402 truncated cone in my nines. I had been using 4.3 gr of Promo (Red Dot equivalent) as a standard load. According to the Lyman Cast bullet Handbook #3 that is a moderate charge; 4.5 gr is max. Lyman #4 does not list a Red Dot load for that bullet. Just yesterday I was browsing my Speer #10 Reloading Manual, and found that for their 125 gr swaged lead bullet, a max charge of Red Dot was 3.6 gr, with a velocity of 1004 fps.

Now I understand that these are different bullets, with different seating depths, etc. But I do find it hard to believe that a boolit that weighs around four grains less can handle a significantly greater powder charge without difficulty, all other things being equal. BTW I shoot my pet load regularly in both my nines without any sign of excessive pressure.

I don't believe that the load data, as given in the manuals was unsafe at the time of publication; their lawyers would never have allowed them to be published if it were. I am guessing that there are arbitrary safety factors that go into the interpretation of the data, which can change over time, and with different manufacturers.

Wayne

I think you might have something off. 4.2 grains of Red Dot even over a 115gr FMJ is a moderate charge for me. No Chrono here, but it recoils mildly and doesn’t sling the brass into the stratosphere…

As for the 358402, I prefer Unique. It performs better for me, although a little dirtier.


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[Rapier]

Based on conversations I have had with emergency room folks, the 380 normally fails due to lack of penetration. If you concentrate on bullet weight, not speed, you might be better served by the little cartridge. You have a very short barrel, so velocity is lmited by the barrel length. A bit slower and heavier bullet might give you a more harmonious outcome. A 115 VS a 90 would be near 30% increase.

[Kosh75287]

A couple of thoughts:

1.) Not very long ago, the means whereby chamber pressures are measured underwent refinement, and various loads in various calibers that were thought to be safe by the old method of measurement were found to exceed SAAMI specs. I'm not CERTAIN that this was the case with the .380 A.C.P. in particular, but lowering charge weights going forward might have been deemed prudent by in-house counsel, if not the consulting engineer.
2.) My 1970-vintage Lyman reloading manual used the Husqvarna M1907 pistol in .380 (originally engineered to fire the slightly more powerful 9x20mm Browning Long round), which was essentially a larger, more robust and longer-barreled version of Colt's M1903 pocket pistol. I do not know if the pistol used a locking breech in the original caliber, but I think this likely. When Sweden (or whatever exporter) rechambered these pistols to .380, it may have been deemed more cost effective to leave any locking system "as is", rather than remove it. This pistol had a 5" barrel, which is ~43% longer than most pistols chambered for .380 A.C.P. Using propellants with burning rates that are slower than, say, W231, I would expect the somewhat longer barrel length to elevate velocities accordingly, especially if any vestigial locking system was left in place. Even if it was somehow "engineered out", however, it may help explain the velocities of Lyman's loads from that vintage of manual, and the higher-than-I'D-expect velocities developed with 115 gr. cast projectiles. The use of the Husqvarna may not explain the "warmth" of later .380 A.C.P. loads developed in "true" pocket pistols, but recall that the Llama MIII-A .380 A.C.P. pistols were made with locking breeches as were various runs of the Colt (F.I.E.?) Pony .380 ACP. If later load development was undertaken with such pistols it may explain the higher-performance levels of later data.
I have personal experience with .380 A.C.P. load development in the Llama MIII-A pistol. While we never achieved true 9mmP performance, we certainly equaled and slightly exceeded 9x20mm Browning Long stats. And yes, the little pistol DOES hurt to shoot when stoked with higher-performance loads.

[TD1886]

A couple of thoughts:

1.) Not very long ago, the means whereby chamber pressures are measured underwent refinement, and various loads in various calibers that were thought to be safe by the old method of measurement were found to exceed SAAMI specs. I'm not CERTAIN that this was the case with the .380 A.C.P. in particular, but lowering charge weights going forward might have been deemed prudent by in-house counsel, if not the consulting engineer.
2.) My 1970-vintage Lyman reloading manual used the Husqvarna M1907 pistol in .380 (originally engineered to fire the slightly more powerful 9x20mm Browning Long round), which was essentially a larger, more robust and longer-barreled version of Colt's M1903 pocket pistol. I do not know if the pistol used a locking breech in the original caliber, but I think this likely. When Sweden (or whatever exporter) rechambered these pistols to .380, it may have been deemed more cost effective to leave any locking system "as is", rather than remove it. This pistol had a 5" barrel, which is ~43% longer than most pistols chambered for .380 A.C.P. Using propellants with burning rates that are slower than, say, W231, I would expect the somewhat longer barrel length to elevate velocities accordingly, especially if any vestigial locking system was left in place. Even if it was somehow "engineered out", however, it may help explain the velocities of Lyman's loads from that vintage of manual, and the higher-than-I'D-expect velocities developed with 115 gr. cast projectiles. The use of the Husqvarna may not explain the "warmth" of later .380 A.C.P. loads developed in "true" pocket pistols, but recall that the Llama MIII-A .380 A.C.P. pistols were made with locking breeches as were various runs of the Colt (F.I.E.?) Pony .380 ACP. If later load development was undertaken with such pistols it may explain the higher-performance levels of later data.
I have personal experience with .380 A.C.P. load development in the Llama MIII-A pistol. While we never achieved true 9mmP performance, we certainly equaled and slightly exceeded 9x20mm Browning Long stats. And yes, the little pistol DOES hurt to shoot when stoked with higher-performance loads.

You hit part of the nail on the head. Did did review pressure reading and found more cartridged then they wanted that were very high over SAAMI specs. One that scared them was the 10mm.

I have an old Hornady 1967 manual and was talking to a Hornady tech about something in it and he told me burn that manual! He said many loads in it were unsafe. I asked him what's the change. One thing he mentioned was modern powder today isn't exactly the same when that manual was written in 1967. I queried him further and he said the new powders today are more efficient. Haven't you all heard that shooting Elmer Keith's original 2400 powder load with a 240 grain bullet is not advised with the current 2400 powder of today? Something change?

[MakeMineA10mm]

I am running into the same kind of variation with 9mm Para. I shoot the Lyman 356402 truncated cone in my nines. I had been using 4.3 gr of Promo (Red Dot equivalent) as a standard load. According to the Lyman Cast bullet Handbook #3 that is a moderate charge; 4.5 gr is max. Lyman #4 does not list a Red Dot load for that bullet. Just yesterday I was browsing my Speer #10 Reloading Manual, and found that for their 125 gr swaged lead bullet, a max charge of Red Dot was 3.6 gr, with a velocity of 1004 fps.

Now I understand that these are different bullets, with different seating depths, etc. But I do find it hard to believe that a boolit that weighs around four grains less can handle a significantly greater powder charge without difficulty, all other things being equal. BTW I shoot my pet load regularly in both my nines without any sign of excessive pressure.

I don't believe that the load data, as given in the manuals was unsafe at the time of publication; their lawyers would never have allowed them to be published if it were. I am guessing that there are arbitrary safety factors that go into the interpretation of the data, which can change over time, and with different manufacturers.

Wayne

The issue with the lower charge for the swaged bullet is because they know if they run the pressures up so velocity is above 1000fps, leading will occur. Thus, in that particular situation, the “max” charge has nothing to do with reaching “max pressure,” and everything to do with keeping that dead soft lead bullet below the pressure/velocity curve which will suredly result in leading.

[MakeMineA10mm]

Jdgabbard - Regarding your original question: This has come up before in different forums and sometimes magazine handloading columns. It’s a multi-faceted answer.

First, Alliant re-formulated all their extruded and flake powders (including Unique) made in the US in the late 80s/early 90s (around the time old Red Dot became Promo, new Red Dot was the reformulated version, and e3 was yet another improved variation). Generally, the newer versions were faster burning, thus giving higher pressures for the same load. Some loads had to be reduced.

Second, there is the lot-to-lot variation in all of the components, primers, brass, powder, and bullets.

Third, there was the change in pressure testing equipment and standards around that time.

A bit of tolerance-stacking, plus new formulations resulting in faster-burning (higher energy) powders, plus more accurate/stringent testing standards, and there you go…