I noticed these two popular powders are referenced in many threads as the same entity "W231/HP38". Why then does my Lyman reloading manual post a few slightly different powder charge data numbers for some cartridges? Is the difference between the powders so small that I should feel free to substitute one for the other? Please advise.
Is HP-38 really a duplicate of W231?
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Ross226
Member
I have used them interchangeably for many years. In my experience they preform identically and I consider them to be the same entity.
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It's not a duplicate, it's the same powder in different containers; a marketing thing, I guess. Any variation in load data has to do with lot-to-lot variation and probably who's doing the pressure testing, reading the pressure indicators, numbers, etc., and interpreting them.
Hodgon lists the exact same data for both.
scattershot
Member
It’s the same powder.
It is the same.
ArchAngelCD
Moderator, SWCA Member, Absent Comrade
Don't take anyone's word on it, contact Hodgdon and St. Marks powder and ask them like I had many others have done. (same powder they both said)
RDub
Member
According to the National Center for Forensic Science website, they are basically the same.
National Center for Forensic Science Win 231
National Center for Forensic Science HP-38
231
Nitroglycerin
2,4-Dinitrotoluene
Diphenylamine
Ethyl centralite
Dibutyl phthalate
2-nitrodiphenylamine
4-nitrodiphenylamine
HP-38
Nitroglycerin
Diphenylamine
Ethyl centralite
Dibutyl phthalate
2-nitrodiphenylamine
4-nitrodiphenylamine
We see that 231 has one additional ingredient that Hp-38 doesn't, and that is 2,4-Dinitrotoluene.
2,4-Dinitrotoluene - an overview | ScienceDirect Topics
It appears that this ingredient is used as a coating, which might explain the slightly different color between the two. And I don't believe this ingredient has anything to do with how the two perform.
Whenever I've loaded the two together with equal charges and identical bullets in 38 Special, I usually get a slightly higher velocity with HP-38. This usually indicates that HP-38 is slightly faster burning than 231. Not by much, we're talking about maybe 20 fps. As far as loading goes, IMR treats them as identical, I see no reason not to consider them the same.
National Center for Forensic Science Win 231
National Center for Forensic Science HP-38
231
Nitroglycerin
2,4-Dinitrotoluene
Diphenylamine
Ethyl centralite
Dibutyl phthalate
2-nitrodiphenylamine
4-nitrodiphenylamine
HP-38
Nitroglycerin
Diphenylamine
Ethyl centralite
Dibutyl phthalate
2-nitrodiphenylamine
4-nitrodiphenylamine
We see that 231 has one additional ingredient that Hp-38 doesn't, and that is 2,4-Dinitrotoluene.
2,4-Dinitrotoluene - an overview | ScienceDirect Topics
It appears that this ingredient is used as a coating, which might explain the slightly different color between the two. And I don't believe this ingredient has anything to do with how the two perform.
Whenever I've loaded the two together with equal charges and identical bullets in 38 Special, I usually get a slightly higher velocity with HP-38. This usually indicates that HP-38 is slightly faster burning than 231. Not by much, we're talking about maybe 20 fps. As far as loading goes, IMR treats them as identical, I see no reason not to consider them the same.
They’re the same powder. Not all manuals starting charges have the same pressure and velocity, and not all manuals have the same max pressure and velocity. There are plenty of manuals out there that stop well short of max pressure loads. Often times load data for lead bullets stop well short of max pressure. Rarely does load data go right up to the SAAMI pressure limit.
Load data is only a refenrece for what one company was using with a set of very specific components. Rarely do reloaders use the exact same brass, primer, bullet combination so load data needs some safety margin built in. On top of all that different lots of powder may preform differently. Given all that, you will run into load data that varies.
Load data is only a refenrece for what one company was using with a set of very specific components. Rarely do reloaders use the exact same brass, primer, bullet combination so load data needs some safety margin built in. On top of all that different lots of powder may preform differently. Given all that, you will run into load data that varies.
I load rifle, shotgun and pistols and have noticed just very slight
changes in all the powders that I have used over the years.
All the company can do is try to get the new powder blend.... "Close"
to matching the "Spec. Data", in order to be safe for users.
W231 & HP38 are very close from what I have used.....
now if you load shotgun Steel loads with Alliant's new Steel Powder,
there can be a BIG difference from lot to lot, that calls for backing off
to keep pressures in line!!
Have fun.
changes in all the powders that I have used over the years.
All the company can do is try to get the new powder blend.... "Close"
to matching the "Spec. Data", in order to be safe for users.
W231 & HP38 are very close from what I have used.....
now if you load shotgun Steel loads with Alliant's new Steel Powder,
there can be a BIG difference from lot to lot, that calls for backing off
to keep pressures in line!!
Have fun.
Moe Mentum
Member
The only difference is the price..... For some reason w231 cost more.
oneounceload
Member
Same assembly line, different labels in the machine.
Jim Watson
Member
Once upon a time, Winchester marketed their own products and Hodgdon sold only theirs contracted from St Marks and others. (Hodgdon does not MAKE smokeless powder.)
So, even though it was the same powder, there was the possibility of lot variations of several percentage points leading to different load data.
Now, Hodgdon distributes both brands, so it is all out of the same bulk shipping container.
So, even though it was the same powder, there was the possibility of lot variations of several percentage points leading to different load data.
Now, Hodgdon distributes both brands, so it is all out of the same bulk shipping container.
Arisin Wind
Member
Seems they are the same.
BlackTalonJHP
Member
I haven't found many trademark owners that will license their trademark without being paid.
As far as them being the same, Chris Hodgdon says they are and that's good enough for me.
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I think the industry allows for a very small percentage variation from lot-to-lot, 3% or something of that order. This would account for slight velocity / pressure differences. Nevertheless, the figures are measurable.
Someone here smarter than I am may know better what the allowable percentage of batch-to-batch variation is.
Someone here smarter than I am may know better what the allowable percentage of batch-to-batch variation is.
Sistema1927
US Veteran
Same thing with W296 and H110.
Willyboy
Member
HP38 vs W231
I contacted Hodgdon and they said the powders are the same. Willyboy
I contacted Hodgdon and they said the powders are the same. Willyboy
