Skeeter’s 357 magnum load 358156 w/2400 in 38 SPL Cases

[Larry Gibson]

Skeeter’s 357 magnum load 358156 w/2400 in 38 SPL Cases

There has been a recent thread and numerous other discussion of Skeeter Skelton’s 357 magnum level load in 38 SPL cases using the 358156 cast bullet seated to the 2nd crimp groove and loaded with 2400 powder. Skeeter loaded these for use in 357 Magnum revolvers back in the ‘60s and used and recommended them through the ‘70s when 357 Magnum cases were hard to come by except from factory ammunition. There was a plethora of 38 SPL cases available as it was the predominant LE cartridge in use throughout the country. The 38 SPL case was readily available to the general public for little cost if any.

Skeeter used the 358156 seated out to its 2nd crimp groove as that was what it was designed for. While seating the 358156 out to the 2nd crimp groove increased the case capacity in the 38 SPL case doing so still did/does not give the 38 SPL the same capacity as with the same bullet seated in the 357 Magnum case to the 1st crimp groove. I started loading for the 38 SPL and 357 Magnum. Skeeter’s load recommendation was to use 13.5 gr of Hercules 2400 but I found using 12.5 gr was a very good load in my Ruger Blackhawk and Colt Trooper. I got my first Oehler chronograph back in the early ‘70s and found the 12.5 gr load of 2400 under the 358156 seated to the 2nd crimp gr in 38 SPL cases often equaled many 357 Magnum velocities out of those revolvers.

There is a lot of discussion and consternation as to whether it is “safe” to use such a load in S&W N frame 38/44 Outdoorsman revolvers and 357 magnum revolvers. I recently conducted a pressure test of the 38 SPL case loaded with a 358156 seated to the 2nd crimp groove loaded over Alliant 2400 to give some guidance for each to make their own decision as to the “safety” of such and whether to use such. I also, just prior to the beginning of that test pressure tested five factory 38 SPL loads and my own standard load with the 358156 over 2400 in 357 magnum cases as a “reference" ammunition.

The picture shows the Contender 357 barrel of 7.94” length with a strain gauge attached and connected to an Oehler M43 PB used for pressure testing. A Ruger Security Six with 6” barrel was used to chronograph my old load previously mentioned. Also shown are the factory rounds tested as a “reference” along with the 38 SPL case with the 358156 seated to the 1st crimp groove, a 38 SPL case with the 358156 seated to the 2nd crimp groove, a 357 Magnum case with the 358156 seated to the 1st crimp groove and a 358156 cast bullet as used.

Attachment 274839

There are several things we should remember and understand. The first is the SAAMI MAP for the 38 SPL is 17,000 psi, the MPLM is 17,500 psi and the MPSM is 18,300 psi. The SAAMI MAP for the 38 SPL +P is 20,000 psi, the MPLM is 20,600 psi and the MPSM is 21,500 psi. The SAAMI MAP for the 357 magnum is 35,000 psi, the MPLM is 36,100 psi and the MPSM is 37800 psi. While ammunition manufacturers and current load manuals strive to keep the pressure under the MAP for those cartridges under some circumstance the MPLM and MPSM are still acceptable pressures.

Another thing we must understand and remember is neither pressure measurements or velocity measurements are absolute. Even with the same ammunition tested in the same firearm we find both velocity average and psi average for a test of sufficient sample can vary, sometimes significantly. If we chronograph the same load or, in my case also pressure test the same load, especially at different times under some different conditions we will find there is a +/- range. As long as the test average result falls within that +/- range of either velocity or pressure we can assume all is well. That is how the technicians in the labs do it. It’s also why we don’t see a lot of actual pressure figures for many loads and/or factory ammunition. There is a pretty wide range of not only velocity but also pressure that is acceptable by SAAMI standards.

Thus, the results of different test I post here and elsewhere may not always agree precisely with any other similar test results posted. Additionally, I’ve come to understand that when comparing similar weight cast bullets in any handgun cartridge the seating depth (not to be confused with the OAL) and the bearing surface have more affect on pressure than any small difference in weight. Note in the picture of the two 38 SPL cartridges on the left how the bullet seated to the 2nd crimp groove increases the case capacity. Note also the longer length of the Magnum case even with the bullet seated to the 1st crimp groove still has a larger case capacity.

Attachment 274840

The 358156 bullets were cast of COWWs + 2% tin, AC’d with a BHN of 12 – 14 after 14 days. The bullets were sized .358 in a Lyman 450 with Hornady GCs crimped on during sizing/lubing with BAC. The bullets weighed 162 gr fully dressed.

All tests were 10 shots of each load as per SAAMI Standards.

Ambient temperature during the tests ran 52 – 60 degrees. Humidity ran 35% with a barometric pressure hovering around 29.75.

I’ll list the load, the muzzle velocity, the velocity SD/SD [in fps], the pressure, the SD/ES {in psi]

The test of the five factory loads;

Speer 158 lead SWC 38 SPL….874 fps….15/43…..15,500 psi….900/2,400

Remington 158 LRN 38 SPL….899 fps….11/34….15,300 psi…..900/3,000

Remington 125 JHP +P….1149…..28/91….15,200 psi…..700/2,200

Remington 148 HBWC 6138….818 fps….19/63….15,000 psi….1,700/5,800

Remington 148 HBWC R38S3….805 fps….9/23….13,900 psi....600/1700

All the above velocity and pressure test results are consistent [+/-] with previous tests of the same ammunition in the same test barrel.

The test of my standard 357 Magnum load with the 358156, seated to the 1st crimp groove [OAL; 1.597”], using 14.0 gr Alliant 2400 in Winchester 357 magnum cases with CCI 500 primers;

357 Magnum SL….1548 fps….20/75….34,600 psi…..1,800/6,000

Test results of Alliant 2400 from 11.0 to 13.5 gr in ½ gr increments of Alliant 2400 in Winchester 38 SPL cases with the 358156 seated to the 2nd crimp groove [OAL; 1.517”] with CCI 500 primers.

11.0 gr 2400….1275 fps….23/72….24,900 psi….1,400/4,400

11.5 gr 2400….1349 fps…..20/69….28,700 psi….1,500/5,100

12.0 gr 2400….1358 fps….21/69….28,800 psi….800/2,500

12.5 gr 2400….1445 fps….24/73….33,200 psi….200/600

13.0 gr 2400….1486 fps….19/56….35,000 psi….2,500/7,3000

13.5 gr 2400….1531 fps….24/89….37,900 psi….2,100/7,100

Chronograph test (same Oehler M43 PBL) of the 12.5 gr load of 2400 in the 38 SPL cases with the 358156 seated to the 2nd crimp groove in the Ruger Security Six. Average is of 10 rounds in the test.

12.5 gr 2400….1251 fps…..23 fps SD….58 fps ES

Note in the pressure test this load proved to be the most uniform. The velocity loss between the 7.94” Contender solid barrel and the 6” barrel of the Ruger was 175 fps. Giving 1250 fps at 33,200 psi definitely ranks the load right “in there” with most 357 Magnum factory rounds using 150 – 158 gr bullets. I was shooting with the barrel at the ejector rod housing resting on sandbags aiming at 6 o’clock on a 50 yard pistol bullseye. All 10 test shots went into the 10 ring. That’s about as good as I can do anymore. That load was an excellent one many years ago when I was using it and it obviously is today.

As to Skeeter’s load of 13.5 gr, that load is over the SAAMI MAP for the 357 magnum cartridge but still within the MPLM and MPSM. Ballistically it is very close to my standard 357 magnum load of 14 gr but does give higher pressure. That, again is due to the lesser case capacity of the 38 SPL case even with the 358156 seated out to the 2nd crimp groove.

[45DUDE]

Thanks- I have this mold and will pin this info on the wall . I am in the reload room almost every day. I think the 11 grains in a 38 case on the second crimp making it the same length as a 357 will be plenty hot enough for me and my Marlin. Jack

[downzero]

That is no joke. And WAY beyond anything I'd try in a 38 case, N frame or no N frame.

[jonp]

Thanks for the testing, Larry. I have some of those and a Blackhawk which is my testbed for all new things.

[dbosman]

Thank you for your work, and sharing it. I've shot a lot of those Skeeter loads, and generally not found them comfortable. Now I know why.

[smkummer]

Good info Larry. I have the article written by Skeeter in the 2nd edition of the Pistol & Revolver digest (1979). It appears the guns he used were all 357 chambered guns. 2 model S&W large frame model 27s. Ruger Blackhawk and a Colt 357 ( same as original colt trooper 357). So no small frame S&W model 19 and the L frame had not yet been produced. Again, as mentioned above, while a 38 special case was used, these loads were intended for .357 chambered firearms.

[Pioneer2]

I have the same Security Six and was looking at buying that mold.Will have to give some of those a whirl.

[Bazoo]

I appreciate the effort you've put into this Larry.

[Tim357]

Thank you Mr Gibson for your legwork with this project. I too loaded 12.5 2400 in WCC +P+ cases, only i used the Ideal 357446 bullet seated to, and crimped in, the second lube groove. My observed velocities in a 3" bbl Ruger SP101 were 1158 fps avg, with ES 16, SD5. I found the load in the 1979 edition of Pistol and Revolver Handbook.

[DaveM]

That is great information. Thank you.

[Forrest r]

Interesting that 12.0gr load flatlined

[Larry Gibson]

Interesting that 12.0gr load flatlined

I wouldn't give a lot of credence to it having "flatlined". Note where I said; "Another thing we must understand and remember is neither pressure measurements or velocity measurements are absolute. Even with the same ammunition tested in the same firearm we find both velocity average and psi average for a test of sufficient sample can vary, sometimes significantly. If we chronograph the same load or, in my case also pressure test the same load, especially at different times under some different conditions we will find there is a +/- range. As long as the test average result falls within that =/- range of either velocity or pressure we can assume all is well. As long as the test average result falls within that =/- range of either velocity or pressure we can assume all is well."

The 11.5 gr fps could have been simple at the high end of it's +/- range of test averages. The 12.0 gr load could easily have been at the low end of it's +/- range of test averages. Thus they appear to be very close together. The next test could give a more uniform spread or could give a greater spread. When comparing incremental load developments such as this an appearance of 'flatlining" between load increments is often encountered. The fewer the shots in the incremental test samples the more likely it will happen. As we see, even single tests of 10 shots per increment can give misleading impressions.

Tests of less than 10 shots, especially those of just 3 or 5 shots can be very misleading. A recent thread had a video of a test of "different primers" in the same cartridge. The test involved the 9mm P cartridge showing the velocity and pressure difference between CCI 500, CCI 550 and CCI 400 (SR) primers. The test was done with only 3 shots per primer. The tester did not state what powder or charge was used. There was some subtle difference between the 3 shot test of each primer yet not enough to put the psi over the SAAMI MAP for the cartridge. Thus it was assumed and so stated to be "safe' in switching primers. While that may apply [still questionable w/o a more comprehensive test] to the 9mmm cartridge and that charge of whatever powder I would not bet the farm it applies to other cartridge and loads of other powders. Switching primers, especially using SR where SP primers are normally used, can have a greater effect of pressures than the video led us to believe.

[fivegunner]

Thank you Larry for posting this .

[rintinglen]

Thank you so much for this post. Extremely useful info especially for those of us who remember shooting these.

Back in the 70's I shot several thousand of the Skeeter loads through my old Model 27. It was stout, but it was much more accurate than the old WW Super X lead solder that would coat the bore in a dozen shots. I found it to be extremely accurate, sometimes grouping 6 shots touching at 25 yards. These days, my 357 shooting is pretty minimal thanks to a cycling accident and the resulting wrist injuries, but I would still be very happy with this in my model 28 or Ruger Security six. My model 66? not so much.

[MT Gianni]

Nice to know pressures. My Rossi 92 really likes this load.

[Murphy]

Thanks for the post Larry, very informative.

Looking back, Skeeter Skelton influenced me tremendously starting in the late 70's when I began reloading, and then casting. I couldn't find a source for this Thompson design #358156 bullet Skeeter spoke so highly of. I scoured the popular gun rags of the time looking for adds to buy them. I waded through Shot Gun news to come out every month and would scour it as well. Nope, never did find a place to order any. So, guess if I want them that badly I'm going to have to learn to cast them myself. There was also another bullet he spoke of, that Keith fella's #429421.

I guess if Skeeter were around today and I had the chance to have him visit me, it'd be off to the reloading room. I would then point out a 5 gallon bucket of 38 Special brass, another 5 gallon bucket of .357 brass, a 3 pound coffee can overfilled with Lyman #358156 bullets cast and ready for sizing, lubing. A big jug of Unique, one of 2400 and a case of primers. I would most likely say "Look what you did!". Then I'd smile at him, offer him a handshake and a thank you.

Murphy

[Forrest r]

I wouldn't give a lot of credence to it having "flatlined". Note where I said; "Another thing we must understand and remember is neither pressure measurements or velocity measurements are absolute. Even with the same ammunition tested in the same firearm we find both velocity average and psi average for a test of sufficient sample can vary, sometimes significantly. If we chronograph the same load or, in my case also pressure test the same load, especially at different times under some different conditions we will find there is a +/- range. As long as the test average result falls within that =/- range of either velocity or pressure we can assume all is well. As long as the test average result falls within that =/- range of either velocity or pressure we can assume all is well."

The 11.5 gr fps could have been simple at the high end of it's +/- range of test averages. The 12.0 gr load could easily have been at the low end of it's +/- range of test averages. Thus they appear to be very close together. The next test could give a more uniform spread or could give a greater spread. When comparing incremental load developments such as this an appearance of 'flatlining" between load increments is often encountered. The fewer the shots in the incremental test samples the more likely it will happen. As we see, even single tests of 10 shots per increment can give misleading impressions.

Tests of less than 10 shots, especially those of just 3 or 5 shots can be very misleading. A recent thread had a video of a test of "different primers" in the same cartridge. The test involved the 9mm P cartridge showing the velocity and pressure difference between CCI 500, CCI 550 and CCI 400 (SR) primers. The test was done with only 3 shots per primer. The tester did not state what powder or charge was used. There was some subtle difference between the 3 shot test of each primer yet not enough to put the psi over the SAAMI MAP for the cartridge. Thus it was assumed and so stated to be "safe' in switching primers. While that may apply [still questionable w/o a more comprehensive test] to the 9mmm cartridge and that charge of whatever powder I would not bet the farm it applies to other cartridge and loads of other powders. Switching primers, especially using SR where SP primers are normally used, can have a greater effect of pressures than the video led us to believe.

To me it's a good thing to see a flatline!!!

Look for it all the time with a chronograph & rifle/pistol loads. "Accurate" loads tend to be somewhere around where the flatlines are.

[pjames32]

Thanks Larry for the great info and explanation. I shot a lot of the Skeeter loads in the late 70's and early 80's. Sadly my aging body won't handle the recoil anymore. Good memories!

[jonp]

Thank you Mr Gibson for your legwork with this project. I too loaded 12.5 2400 in WCC +P+ cases, only i used the Ideal 357446 bullet seated to, and crimped in, the second lube groove. My observed velocities in a 3" bbl Ruger SP101 were 1158 fps avg, with ES 16, SD5. I found the load in the 1979 edition of Pistol and Revolver Handbook.

How did you find the recoil with that? I found full house 357Mag loads with 158gr unpleasant due to the grip.

[scattershot]

Lotta work went into this, thank you for posting it. As I recall, Skelton said that he only used this load in .357 magnum revolvers, but wouldn’t hesitate to use it sparingly in heavy frame .38s, such as the Colt Official Police or the S&W 38/44. I have that mold, and may have to pour a few. Anyone know if this bullet is available commercially?