Team,

I use Lyman Cast Bullet Handbook 3 Rd Edition and noticed a big difference between HP38 and 231 data. HP38 with the 158 gr 358311 38 Spl +P is 4.5 grs. 231 38 Spl + P data for same bullet is 5.2 grs. I know that this data originates from 1980, it could be that HP38 and 231 were different powders, but Hodgdon told me that they were always the same even when they were different companies (?)... guess they had a third party OEM make the powder for them or had one slow batch of 231.

I have current HP38 (2015 vintage). I'm reluctant to use Lyman 3 231 data using the HP38 for 38 Spl +P loadings.

What are your opinions about this difference and which one to use?

4.2 to 4.9 grs is standard in a lot of old manuals , while the
5.2 loading is a +P maximum load tested in a Universal Receiver
...........

otherwise known as a K frame or "Better".

5.0 grs of w231 with a cci primer in my J frame snub nose
kicked out 816fps but was also one of the "Widest" groups
in twelve powders that I tested.

5.0 grs of Universal, Unique or CFE may work better in the pressure dept. for you.

It would be easy to say lot-to-lot discrepancies account for the differences in data, but if that was true, the discrepancies were often indeed huge ones.

Different pressure equipment, perhaps calibrated differently, with results read and interpreted by operators with varying degrees of skill may have something to do with all this. That might mean actual lot-to-lot differences were much smaller than what they may seem. I think acceptable allowable differences in powder lots sold for handloading are somewhere on the order of around 3% maximum. Perhaps that hasn't always been the case.

As I recall, it's only been common knowledge for the last 10 -15 years that HP-38 and 231 were the same.

One can look up old HP-38 and 231 data in handloading manuals or such excellent works as Ken Waters PET LOADS series. Waters, though long-retired, was among the very best of the handloading writers during the past fifty years or so. However, his data was not pressure tested. He used traditional, accepted methods ("eyeballing") for determining safe / maximum loads. Some such methods are still recognized today, some aren't.

About the only way for handloader to make a safe determination is through real education (not "Internet instant results") and the use of a chronograph.

Pressure-tested data in recent and fairly recent manuals should be more accurate than some of the older stuff. I'd be inclined to go with such data and verify by chronographing. To further add to the confusion, look at the current Hodgdon data for HP-38 / 231: charge weights identical, but much lower than Lyman. Perhaps coincidentally, perhaps not, my old notes show powder charges of 231 .38 Special loads and #358311 are midways between Hodgdon and Lyman data.

Most importantly, remember this is the Internet and I'm no expert. Good luck-

I've seen the same wild differences between the Lyman and Hodgen data for 231/HP-38 and can't explain the difference. I did note that the pressures shown for the max. loads in the Hodgen data do seem low, especially for +P equivalents. That being said, I do shoot 4.8-4.9gr. of HP-38 with a MBC 158gr. coated SWC and find it to be a manageable, but stout load in my 642; less so in my Model 60.

Several propellants sold under both the Hodgdon and Winchester brands are manufactured by St. Marks Powders, a division of General Dynamics, in their plant in St. Marks Florida. Among these are H-110/296, and, HP-38/231.

I had a conversation several years ago with an engineer at St. Marks specifically about H-110/296 when there was still disagreement about whether they were identical. This was before Hodgdon became the distributor for the Winchester brand! He finally admitted that they were absolutely identical! I asked if there were any other powders they manufactured for Hodgdon/Winchester that were also identical, and his answer was NO. However, since Hodgdon has become the distributor for Winchester Hodgdon now claims that HP-38 and 231 are, in fact, identical. I can see no reasonable to doubt what Hodgdon says!

Now, let's address differing data in the same manual for each of these pairs of propellants. Logic would say that if identical that developed data should be identical, subject to very small differences as a result of lot-to-lot variation! In the Hodgdon manuals you will see that the data is identical as would be expected.

But, go to Sierra of a few years ago for example, or Speer, Hornady, etc. You see significant differences between H-110 and 296, or H-38 and 231. Is this necessarily because they were that different, or simply that loads were developed simply by the technicians "instinct" (gut feeling), "pressure signs" (hardly dependable at rifle pressures, worthless for handgun cartridges!), or because they did not actually pressure test all of the data as most people seem to believe! The hard, cold, fact of the matter is, while some data is pressure tested, that the majority of loads are calculated from a base pressure level with that powder and bullet! Why do you think, Sierra for example, shows loads to achieve a specific velocity, and not a simpler minimum/mid/maximum load like Speer does? Have you ever noticed that the Speer "Starting load" is usually simply their "Maximum load" minus 10%?

A prime example of the fact that much data has not been tested in the "magic" Speer Number 8 manual with some absolutely terrifying data for .38 Special, 125 gr JHP, and SR-4756! I won't repeat the data, but at the same time IMR was publishing a maximum load for this combination, at 15,000 PSI, that was less than 1/2 the Speer load. If I recall correctly the Speer starting load was more than twice the IMR Maximum! And this was supposed to be a Standard Pressure .38 Spl. load as the Speer #8 was published before the +P standard was established in 1972!

__________________
Gunsmithing since 1961

All of the controversy over the old 38 spl in the last 30+
years with the +P vs std pressure ratings and the wide
disparity in published data along with the confusion about
powders has created a generation of handloaders so fearful
that I'm surprised they even dare to load the old 38.
Questions posted on here usually result in lots of answers
that are simply opinions and have no relevance to what
reliable data is available. I think Alk is right in that lots of
data in manuals was published without actually being
pressure tested. I truely doubt that anyone will ever see any
load that exceeds the 20,000 psi limit for +P listed in any
manual that does pressure test their loads. Also I remember
a product evaluation of W231 way back when it was new that
strongly emphasized that 231 was designed to be consistant
from lot to lot by volume, NOT scale weight because most loaders used measures instead of scales. This was either not
read by most handloaders or just ignored because they just
know better. And lastly I am bemused by all the handloaders
who seem nearly scared to death to load steel K frames
with anything but light 38 spl plinking loads when a fairly
common practice by "gunsmiths" back in the late 60s-early
70s was rechambering K frame 38 spls for the .357 mag ctg.

In the 1980 Lyman 3rd Edition Cast Bullet Handbook the +P load data for W231 was 5.2gr with bullet #358311. (as stated in the OP)

In the Lyman 4th Edition Cast Bullet Handbook which was published in 2010 with the same #358311 bullet and W231 is the same 5.2gr for a +P load.

I understand the reluctance of the OP to use that data with today's HP-38 but that 2010 data was published by Lyman well after it was verified both W231 and HP-38 are identical powders. I hope this puts the OP's mind at ease, according to Lyman you are safe using the higher charge weight with HP-38.

__________________
Freedom is never free!!
SWCA #3437

Thank you everyone for your advice and excellent information.

I would tend to think the W231 and HP38 powders, even though the same powder, could have been from different lots, tested at different times, and possibly different equipmet...

231 has been my "go to" powder for many years in 38,9mm, and 45acp. I just chrono'ed some 9mm loads with 4.5 gr. 231 behind a 124 gr Jacketed HP. From a 3 1/2" barrel it did 821.8 FPS, with 10.92 Extreme Spread, and a Standard Deviation of "3.87"! Any time I can get that kind of consistency I'll continue to stay with it. It may not be quite as clean burning as some others, but the results are worth it.

__________________
H Richard
SWCA1967 SWHF244

With a 124gr JHP bullet give 4.6gr to 4.8gr W231 a try and see how much cleaner those loads are.

__________________
Freedom is never free!!
SWCA #3437

per post #10;

A full load of w231 in my C9 3.5" with a 124gr plated bullet at 1.14"
goes across my chrony at 1014fps for its top speed.

4.2grs in the little 3" Kahr does 913fps for a X-Lite target load that is very accurate and at POA.

4.8grs with a jacket 124gr bullet is getting up there but still plenty safe for a 9mm pistol. Might be around 950fps ?

You might look into some new manuals also.......... they are only $6.50 or so with updated data from
that old rag you are using.