Win 231 and HP38 the same powder, but I still have a question.

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Wildbillz

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Hi All
So I have read it here that 231 and HP38 are the same powder under a different label. Cool I am good with that. Today I find I am almost out of Win231 so I figure I swap over to HP38. I checked my powder prior to starting and found that it was dropping 4.4grns instead of the 4.2grns which I had it set up for with the Winchester powder? So re zeroed my scale. Set my scale back to 4.2grn and did a few more drops. Everyone was 4.4grn. Cleared the powder dropper and poured in Win231, ran 16 drops to settle the powder out in it. Then I weighed several drops of the Winchester and it was back to 4.2grn. I never made any change to the powder dropper (Dillon) but was still getting a 2/10th of grain change. I checked the data from a couple of sights and it was still within the starting limits so I ran 50 rounds and took them to the range to test for function. Everything ran fine and there were no signs of over pressure so they should be good to go. I just find it odd I was getting the shift without having made any adjustment to the powder dropper. Any ideas?

Thanks in advance
WB
 
I always throw a few charges on the scale to make sure I am adjusted correctly to start. Keep your powder hopper at least half full. If you do that and still find your charge weight changes to a significant degree, you should look to a problem elsewhere.
I weigh case 25 as well as case 50 and they are always the same.
 
Different lots of powder might drop slightly different than an older lot. It seems reasonable to me with such a slight difference in weight. As much as they try it's impossible to make each batch identical.

Makes sense to me.

WB
 
That was something I learned from this site.

Different lots of the same powder can drop different. I'd never considered it until I read it here and it seemed quite plausible.

Now, surprisingly enough, with bullseye. Just yesterday when I got down to 1/3 of a hopper on my Dillon out of my current one pound can, I poured it into a new can that I just opened, mixed it thoroughly, and poured in new to the hopper. From there I recalibrated with no change.

I had used a sharpie and wrote an open date right over the lot number (dumb) so for all I know they were actually the same lot
 
Load a few at 4.2 Grs, then adjust the measure to throw 4.4 grains of HP-38 and load a few, shoot them over a chrono if you have one while shooting groups and see what it does.

Like this.
Load # 107 .38 Spl 18 shots.jpg
 
I load on a Lee classic turret press with the auto disk powder measure. Since the disc measures by volume not weight, I always check powder drops with my balance scale. I have seen similar discrepancies in different lots of powder. Loading 357 with win 296 at 15-16 grains per drop, differences in humidity can cause a .1gr difference within the same jug of powder. Recently finished a pound of Win296 and opened one of H110. The H110 consistently measures about a tenth over what the 296 did for the same volume
 
The powder sold to the public is blended by weight to give a consistent pressure curve with previous lots. Faster and slower lots are blended so the pressure curve, by weight, is plus or minus 10% with their standard. It is not blended by volume, so that equivalent volumes of powder give a consistent pressure curve. You never see reloading manuals give loading data in microliters (4928.92 microliters to a teaspoon!) because reloading companies don't control the density of their product. They correlate weight with pressure, not density or volume with pressure. And you are throwing a volumetric charge with your Dillion powder horn.
 
Agree with Jonesy814. When I restarted loading a few years ago I started with a Lee Auto Disk measure and HP-38 powder. After about a month of restarting and becoming familiar with the equipment I decided one night to go thru the 2 disks I use to reload pistol and record what each cavity was dropping. That was 8 cavities in whole and thought I was were I wanted to be and had a good feeling for what I would get with each cavity. That was until one time I went to start a new load with a different bullet so I put in the disk with the cavity that would get me where I wanted and measures up the same powder from the same jar as I did the test. To my surprise they did not come up the same. I still have the notebook I did the original study on.

So yes I agree that once open a powder will not necessarily remain static, weight X volume. I do wish I had a place to set up a chrono and test this but I doubt there is much actual different in performance.
 
Slamfire said a mouthful!!!!! Density varies for a number of reasons. Cannister powders are blended (mixed) to get a consistent burn rate so their weight per cubic measure may vary slightly from lot to lot.
 
I do most of my loading on a Lee Classic Turret, with a Lee AutoDrum mounted.

I fill the hopper, and run the turret around about 10 times to settle the powder. Then I check the charge weight with a 5-0-5 scale. With 2400 powder, for instance, I check at 5, then 10, then 30 loads, but it is within .1 grain every time. I usually run 50+ loads before bothering to check again.

I find the measure very accurate, but generally need to make minor adjustments when changing to a different lot of powder.
 
Different lots of powder might drop slightly different than an older lot. It seems reasonable to me with such a slight difference in weight. As much as they try it's impossible to make each batch identical.
This I've had .2gr difference between lots
 
Load a few at 4.2 Grs, then adjust the measure to throw 4.4 grains of HP-38 and load a few, shoot them over a chrono if you have one while shooting groups and see what it does.

Like this.
View attachment 872208

Hi Walkalong
So I did that (sort of I just wanted to see the velocity so I didn't shoot for groups) today. I fire 5 rounds of each and here is what I got. This is the first time I have used the Chronograph. Its a CED M2. So other then Velocity what is it trying to telling me that I may not understand?

CCI 124grn TMJ Lawman ammo (as a control of sorts)
1011 FPS, 1023 FPS, 1027 FPS, 1031 FPS, 1009 FPS. High1031 Low 1009 ES 22 Ave 1020.2

4.2grn Win 231, 124grn FMJ
937.5 FPS, 988.9 FPS, 976 FPS, 975.7 FPS, 954.1 FPS. High 988.9 Low 937.5 ES 51.4 Ave 966.4

4.2grn HP38 124grn FMJ
1020 FPS, 1024 FPS, 992.9 FPS, 1027 FPS, 1022 FPS. High 1027 Low 992.9 ES 34.1 Ave 1017.2

4.4grn HP38 124grn FMJ
1035 FPS 1063 FPS 1030 FPS 1066 FPS 1050 FPS High 1066 Low 1030 Es 36 Ave 1048.8

So looking at this the HP38 is running them a little faster then the 231, age of the powders and different lots? This would be my guess. The 4.2grn of HP38 was closer to the CCI Lawman ammo control group only off by 3 FPS if I am understanding it right? Between the two 4.2grn loads the difference was 50.8 FPS. Not a huge difference, but interesting. I am going to guess that this would also be age and lot differences in the powders? The 4.4grn HP 38 load was only 31.6 FPS higher then the 4.2grn load and only 28.6 FPS faster then the control load.

I just wanted to take a moment and share this. The Chronograph will be an interesting addition to my reloading.

WB
 
I've been reloading since I was a kid with my father using a Herter's C press.

As Wildbillz said often there are differences with replacement powders. I learned that with 4831, H4831 and IMR4831.
 
If you find a magic load, the old timers will tell you, it would be wise to buy as much of that powder with the same lot number you can.

Lot numbers change, variables change.
 
If you go back far enough you'll see there's totally different data for 231 and HP-38. I've got the printed manuals to prove it.
 
If you go back far enough you'll see there's totally different data for 231 and HP-38. I've got the printed manuals to prove it.
And that is due to the 2 versions being tested in different facilities and different types of testing equipment.

Why in the world would St. Marks Powder and in turn General Dynamics lie?

You would think after all these so many years this would be settled.
 
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