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Thread: SAAMI pressures for .38 Super

  1. #11
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    Quote Originally Posted by PolyKahr View Post
    I have been looking at a number of powders and trying different loads for reloading the .38 Super round. In the Hodgdon reloading data, they indicate for Winchester 231 powder and a 115 gr LRN bullet, a powder charge of between 4.9 grains and 5.7 grains the last resulting in a pressure of 30.700 CUP. This also results in a velocity of 1,191 fps. The SAAMi spec pressure however, is 36,500 CUP which would in all likelihood result in a velocity much greater. Does anyone know why the powder companies set their maximum charge weights so far below the maximum SAAMi pressure without even getting to, in this case, 1300 fps?

    I realize part of the issue is simple precaution. And yes, I subscribe to all the start low and build up, precautions that will no doubt accompany responses to this post. But Buffaloe Bore has .38 Super rounds that achieve muzzle velocity of 1410 fps. While I don't necessarily want to go full out wild cat, this round typically did achieve 1300 fps with a 130 gr bullet back in 1929, Are we total wimps today?

    Wade
    Are you using the on-line Hodgdon resource? They have two listings for ".38 Super," which is misleading. There aren't two .38 Supers. The older, parent cartridge was the .38 Automatic. When they started loading it hotter, the name was changed to .38 Super and then +P was added to further differentiate the new, hotter loads from the old .38 Auto load.

    In the Hodgdon on-line data, there are NO loads for the .38 Super +P using Winchester 231. But you will find Win 231 if you look at the loading data for ".38 Super" (without the "+P" -- which should be understood to mean .38 Auto. Consequently, I think you are comparing load data for .38 Auto against the SAAMI maximum pressure for .38 Super +P.

    If you look at the data for .38 Super +P, for a 115-grain bullet Hodgdon only shows data for WSF powder, and the maximum pressure is 34,400. And it's in psi, not in CUP. That's another important distinction -- CUP is not equal to psi, so be sure you're not mixing units of measurement. Where are you finding Hodgdon data listed in CUP?
    Hawkmoon
    On a good day, can hit the broad side of a barn ... from the inside
    Likes (1) :
    PolyKahr (3rd June 2018)

    Last edited by Hawkmoon; 3rd June 2018 at 10:22.


  2. #12
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    Hawk,
    You are correct that the Hodgdon site only mentions one powder choice for .38 Super +P and that those pressures are indeed measured in PSI. I was using the loads under .38 Super, which are distinct from .38 Auto. The first line gives Lil'Gun with a maximum loading of 13.0 gr, 1315 fps, and pressure of 26,600 CUP. Yes, I know the difference. In any case, thanks for highlighting the issue because I can make a mistake Sorry to take so long to get back to you on this, but I have resolved the issue to at least my satisfaction for now.

    Wade

  3. #13
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    Quote Originally Posted by PolyKahr View Post
    Hawk,
    You are correct that the Hodgdon site only mentions one powder choice for .38 Super +P and that those pressures are indeed measured in PSI. I was using the loads under .38 Super, which are distinct from .38 Auto. The first line gives Lil'Gun with a maximum loading of 13.0 gr, 1315 fps, and pressure of 26,600 CUP. Yes, I know the difference. In any case, thanks for highlighting the issue because I can make a mistake Sorry to take so long to get back to you on this, but I have resolved the issue to at least my satisfaction for now.
    Well, you have me confused. Whether or not you include the +P, .38 Super is functionally the +P variant of .38 Auto. .38 Super (without the +P) is not the same as .38 Auto. But Hodgdon doesn't show anything for ".38 Auto" -- they only have .38 Super Auto, and .38 Super Auto +P. Looking at the loads and pressures they show for .38 Super Auto, it seems clear that what they are calling ".38 Super Auto" are in reality .38 Auto loads. Further, the Hodgdon on-line loading data center doesn't show Lil'gun as a powder choice under either .38 Auper Automatic or .38 Super Automatic +P. So I don't know what you're looking at when you say the first line gives Lil'Gun ...

    You also said that SAAMI pressure for the .38 Super is 36,500 CUP. But the SAAMI web site doesn't list pressures in CUP, they use psi. And they don't list any .38 Auto pressures for a 115-grain bullet. For .38 Auto with a 130-grain bullet, the SAAMI maximum pressure is 26,500 psi. Moving to .38 Super Automatic +P, the SAAMI data do include a 115-grain bullet, and for that they show a maximum pressure of 36,500 psi.

    http://www.saami.org/specifications_...essureData.pdf

    I'm glad you have an answer to your satisfaction, and I wish you would post what you came up with for the rest of us. I'm curious, because I can't find any data that corresponds to what you posted, so that makes me even more interested in where you went with your search.
    Further, I can't find any load data on the Hodgdon web site for Lil'Gun with a 115-grain bullet, nor can I find any data for .38 Auto. So I don't know what you're looking at.
    Hawkmoon
    On a good day, can hit the broad side of a barn ... from the inside
    Last edited by Hawkmoon; 3rd June 2018 at 12:09.


  4. #14
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    Hawk,

    I didn't mean to be confusing,and I can tell that you are irritated with me. Here is the Hodgdon data from their website:

    http://www.hodgdonreloading.com/data/pistol


    Putting in the chart for Select Cartridge: .38 Super Auto, for Bullet Weight: 124 gr and for Powder: Any yields the following:

    Hodgdon Lil'Gun .356" 1.250" 12.5 1,271 23,100 CUP 13.0 1,315 26,600 CUP
    Hodgdon Longshot .356" 1.250" 5.9 1,140 22,400 CUP 6.8 1,286 31,300 CUP
    Winchester 572 .356" 1.250" 5.8 1,160 26,100 PSI 6.7 1,297 35,300 PSI
    Hodgdon HS-6 .356" 1.250" 7.1 1,160 26,100 CUP 8.0 1,280 32,500 CUP
    Hodgdon CFE Pistol .356" 1.250" 5.8 1,170 26,100 CUP 6.4 1,260 32,200 CUP
    Winchester AutoComp .356" 1.250" 5.7 1,126 25,100 CUP 6.3 1,222 32,100 CUP
    Hodgdon Universal .356" 1.250" 4.8 1,088 24,300 CUP 5.2 1,182 32,100 CUP
    Winchester 244 .356" 1.250" 5.0 1,119 24,800 PSI 5.8 1,255 34,800 PSI
    Winchester 231 .356" 1.250" 4.7 1,062 26,100 CUP 5.4 1,200 32,400 CUP
    Hodgdon HP-38 .356" 1.250" 4.7 1,062 26,100 CUP 5.4 1,200 32,400 CUP
    IMR IMR Target .356" 1.250" 5.3 1,197 27,400 PSI 5.9 1,286 34,000 PSI
    Hodgdon Titegroup .356" 1.250" 4.3 1,086 25,100 CUP 4.9 1,181 31,000 PSI
    Hodgdon Clays .356" 1.250" 3.8 1,000 26,700 CUP 4.4 1,126 31,900 CUP
    Hodgdon Titewad .356" 1.250" 4.0 1,068 28,600 CUP 4.6 1,140 32,000 CUP

    You will note that pressures are a mixed bag of CUP and psi. Nevertheless, the maximum CUP is 32,400. So, if that corresponds to SAMMI .38 Auto, I accept that these then are for .38 Auto even if listed as .38 Super. Heaven knows I am no expert in this stuff. Also. the outer range using their bullets, in their test barrel, etc, is 1,315 fps. The original loading for .38 Super Auto was 1300 fps. The entire thread was started on the basis that I wanted to achieve 1300 fps, hence, without a chronograph, I must use published data. Therefore, I must be satisfied for now.

    130 gr bullets were the original loading for the .38 Super Auto. I was using Winchester 130 gr FMj when a friend, who happens to compete at the national level suggested that he used 124 gr in his race gun. I tried 124 gr, 0.356 in dia Berry's Plated RN. I do load the bullets a little longer than the published OAL, so there is a variation that may make the bullet slower. Anyway, the loading seems to be more accurate. As far as the 115 gr, I don't know where that came from, I may have mentioned it but I have never loaded a 115 gr bullet.

    Wade

  5. #15
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    Quote Originally Posted by PolyKahr View Post

    As far as the 115 gr, I don't know where that came from, I may have mentioned it but I have never loaded a 115 gr bullet.
    From your first post in this thread:

    I have been looking at a number of powders and trying different loads for reloading the .38 Super round. In the Hodgdon reloading data, they indicate for Winchester 231 powder and a 115 gr LRN bullet, a powder charge of between 4.9 grains and 5.7 grains the last resulting in a pressure of 30.700 CUP.
    You need a chronograph. Especially if you're using Berry's plated bullets.

    I use Berry's bullets. But there's a problem -- they don't publish load data. They say to use "mid-range" data for jacketed bullets. So I started with their 230-grain round nose bullet and a charge of Winchester 231 that should have given me around 800 fps, or a bit more. When I ran them through the chronograph, the average velocity was under 750 fps. I'm now loading them at 5.3 grains of Winchester 231. According to the Hodgdon web site, that's the maximum, and it should be producing 832 fps. It's not -- I'm getting 775 fps.

    Some time ago our member Niemi24s started a project to measure different bullets and to tabulate the measurements. A lot of our members contributed measurements, Niemi entered it all into a spreadsheet, and he put it up on Google Docs. There's a sticky post that has a link to the spreadsheet. What it shows is that there's a big variation in the dimensions of bullets of the same weight. At least in .45 ACP, Berry's plated bullets seem to have a shorter body and a shorter bullet overall length than most jacketed bullets. That means when loaded to the same cartridge overall length, there's less bullet inside the case, which means more volume and less pressure. Less pressure means lower velocity.

    The construction of all Berry's bullets is the same. I haven't measured any of their 9mm/.38 Super bullets, but I expect the same deviation we found for .45 ACP. The printed load data don't provide accurate results for velocity with Berry's bullets. You can't guess at this stuff. There are simply too many variables.
    Hawkmoon
    On a good day, can hit the broad side of a barn ... from the inside
    Last edited by Hawkmoon; 3rd June 2018 at 22:35.


  6. #16
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    Hawk,

    Yes, I need a chronograph. I too load .45 Auto, with 230 gr Winchester FMJ and JHP as well as Hornady 230 gr XTP using Win 231. Its a good powder, no doubt.

    Again, sorry for the confusion. I was on a quest for knowledge that simply is not to be had outside of a powder manufacturer's chemist position. But, in any case, I do need a chronograph to continue my education. The folks here, however, have given me a great deal of new information, for which I thank the members and you in particular for your patience.

    Wade

  7. #17
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    Quote Originally Posted by PolyKahr View Post

    You will note that pressures are a mixed bag of CUP and psi. Nevertheless, the maximum CUP is 32,400. So, if that corresponds to SAMMI .38 Auto, I accept that these then are for .38 Auto even if listed as .38 Super.
    This is not the case.

    SAAMI maximum average pressure for .38 Auto is 23000 CUP, 26500 piezo psi; .38 Super +P is 33000 CUP, 36500 psi.
    32400 CUP is effectively indistinguishable from 33000 CUP, there is more difference than that round-to-round.
    There is some statistical massaging done in setting published pressures and I operate on the basis that if they stop short of the maximum for some combination, they have a reason, mathematical or mechanical.

    Oh, by the way, the current SAAMI velocity spec for a 130 grain bullet is 1200 fps. I suspect the old number of a 130 at 1300 involved wishful thinking and the ad writer liking the alliteration of numbers. Note that even Buffalo Bore, who do a good business crowding the limits, claim only 1350 fps for a 124 grain bullet.
    Likes (1) :
    PolyKahr (9th June 2018)


  8. #18
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    Thanks, Jim. The friend I mentioned who put me onto 124 gr bullets for the .38 Super mentioned that he and his shooting friends load with CFEPistol, as it is a very economical powder. I have also used CFEPistol. At typical self defense distances the I found it to provide satisfactory accuracy.

    Wade

  9. #19
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    Quote Originally Posted by kenhwind View Post
    Me thinks that some of the published results are not necessarily based of pressure but on the overall results. Sometimes more powder which means more velocity but not always better accuracy.
    The 'practical shooting' guys used to load 9 mm to 'Make major.'
    This allowed them to have fewer holes on a larger scoring area on the target since the momentum (AKA 'power factor' of v * W /1,000) was higher.
    It was easier to pull this trick with the larger .38 Super.
    And in a full size 1911 there is more than adequate strength in the smaller chamber diameter (relative to the barrel OD at the chamber) of .38 Super compared to .45 ACP.
    Keep in mind that revolver cylinders can be strengthened buy simply omitting cylinder flutes for a real gain in allowable pressure.
    The next thing is to move bolt notches in the cylinder further to the side relative to the chambers in the cylinder.

    It does not take all that much metal.
    Especially with all the improvements in overall steel strength from using alloys.

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