Continuously Variable Load Data

[Maj Dad]

I swear, I am going to stop looking up new load data - I just loaded up ~25 38 Spl loads, 4.9 gr Win 231 per the Lyman Pistol and Revolver Loading Handbook, Second Edition (1994). For some reason, I looked up the Hodgdon reloading site, and the max load for a 158 swc is 3.7 gr! What in the world has changed so dramatically that a load is dropped by over 2 grain? I will shoot them in a modern heavy bbl M10-10, and I have shot these loads for years with no problem. I know all about lawyering and changed formulations, but that is a 45% reduction - :banghead:

 

[rcmodel]

My guess is that the Lyman book was talking about a cast RN bullet from a specific mold design, and using a specific alloy, specifically, very hard Linotype.
At 16,800 CUP.

Hodgdon is talking about a softer swaged or cast SWC commercial bullet of different design.
At 15,900 CUP.

The Devil is in the fine print!

Just a guess though.

rc

 

[GooseGestapo]

Winchester used to only publish a starting load for their powders.
The new Hodgdon data carrys on this tradition.

Look at HP38 data. It's the exact same powder just packaged in different lableling.
The load you list is approximately a max load for a NON +P load for .38spl from my experience.

I've shot many thousands of 158gr SWC and RN over 3.6gr of HP38/Win231 in PPC competition. Even shot a couple of national records with it.
It's a "start" load that gets ~775fps from a 4" bbl.
4.0gr with a double end wadcutter makes a pretty good "budget" self-defense load. But, it may "blow" the skirt off of a hollow-base wadcutter.

 

[Maj Dad]

I'm familiar with the old Winchester load books & start loads, but the Hodgdon data site ( http://www.wwpowder.com/basic-manual-inquiry.html ) lists identical loads for 231/HP38, & the starting load is 3.1. gr, and max is 3.7. It just doesn't make sense - I have have been shooting these loads for years, too, and then all of a sudden, complete turnabout...

 

[ArchAngelCD]

If you really want to drive yourself nuts look at the 158gr Cast LSWC bullet .357 Magnum load on the Hodgdon site. Their Max charge is 5.0gr which is only 1 tenth below your .38 Special load and Hodgdon is reporting pressures of 23,900 CUP. In a .38 Special case your load might even have pressures higher than that. I hope you're not shooting that ammo in a older .38 Special revolver.

 

[Haxby]

Hodgdon shows the 3.7 gr load at 14,600 cup. 38 max pressure used to be 18,900 cup for standard loads and 22,400 for +P. That's from Speer #10. It looks like Hodgdon is only showing their extra-light cowboy loads for lead bullets in the 38.

 

[Maj Dad]

Archie, no, it's a newer Mod 10-10. I may even trial them in my 686 to see if the powder was magically updated to a near-explosive state. But I still cannot fathom how a previously published starting load is now .5 grain over the new maximum load - what has changed? I know the old Lyman manual loads from the 50's and 60's were way hot (at least according to the subsequent data), but nowadays loads are mostly pressure tested and not simply examined for outward signs of excessive pressure. I called Accurate back when they were still in Tennessee and spoke with one of their main guys (really nice, Czech I think) about the differences in AA#2 Improved. He told me it used the same data as it was just made a little bulkier with no differences in burning characteristics. He also talked about tweaking formulations to do this or that, and then having to re-test and then using the new data (in this case the same). I understand that, and concur with advice to follow the new data. But I've not heard a plausible answer to what has changed so significantly with Hodgdon's lineup...

I am going to write Hodgdon and ask, politely, what's up. Who knows, maybe someone up there will enlighten us.

Edit: I wrote them - we'll see if anyone replies.

 

[ljnowell]

.

I am going to write Hodgdon and ask, politely, what's up. Who knows, maybe someone up there will enlighten us.

Edit: I wrote them - we'll see if anyone replies.

My experience with hodgdon, Speer, and alliant tells me you will get a decent answer they are pretty good

I had a lively discussion with a gentlemen about GDHPs the other day. He insisted they were conventional jacketed bullets, I told him they were plated. I emailed Speer and they replied promptly, with a humorous response confirming what I said.

 

[gamestalker]

It's not at all unusual to see very conflicting data.

I was loading up some 300 win mag. recently, using Speer 165's with IMR-7828, and the data didn't have anything in common with other published data.

Speer - 79.0 - 83.0 gr.

Hornady - 67.8 - 76.8 gr.

Nosler - 76.0 - 80.0 gr.

Hodgdon - 74.0 - 79.0 gr.

Considering I was using Speer bullets, I used Speer data, and the data produced good pressures and velocities. I tried Hornady data with Hornady bullets, and I got excessively low pressure signs and low velocities, even at the maximum. Go figure?

I could easily example a couple dozen other instances in which the data was very broad and contradicting. But it's important to read into the data, often times there is a key detail that explains such huge variations in data.

GS