.357 magnum Ruger GP100 6" barrel

[Taylor]

Lyman 358665 & W231

Load Data:

Lee 2nd Edition Start 6.2--- 6.7 grains

Winchester 2006 4.5---5.0 grains

RCBS Cast Bullet #1 4.9---5.4 grains

Winchester and RCBS are close,Lee on the other hand is quite a bit a head.

Can someone explain the large gap here?

I have not really found anything by researching on line,other than discussion.

[tazman]

The Hodgdon data site has data for that powder and 158 grain cast boolits. Since they manufacture/distribute the powder i would accept their opinion on it.
They call for 5.0 grains max in a 357 mag case.
Here is the link to their site.
http://www.hodgdonreloading.com/

[Taylor]

tazman, I saw that, and I agree,it's just that it didn't make since to me that Lee would be so different.

[robertbank]

Send an email to Lee and ask them. Might make for interesting reading.

Bob

[wv109323]

Most reloading manuals lists the loads for lead bullets at slower velocities than the same weight jacketed bullets. Lead/Cast bullets require some more parameters to be correct to obtain optimum accuracy and velocity. The lead bullet must fit the bore or leading will occur.
What does the manual say for the same weight jacketed bullet?

[bhn22]

When LEE copied Winchesters loading data for 231 in 357 magnum, the copied the wrong bullet information. Winchester shows 6.2 to 6.9 gr of 231 with Hornadys 158 JHP. If you open the 158 LSWC tab, they drop it to 3.4 to 5.0 gr. I have information from someone I trust that LEE doesn't pressure test anything, they just buy or copy reloading data from other companies. There was a similar post last night on a different caliber that had very similar circumstances. Anyway, that's what you're seeing. Some companies list 38 Spl loads for .357 mag when they're dealing with faster burning powders. I knew it had to be something like this because I use 5.2 gr of 231 as a practice load for 38 Spl +P lead hollowpoints in 38 Spl cases, and it's a published load from an older manual.

[tazman]

tazman, I saw that, and I agree,it's just that it didn't make since to me that Lee would be so different.

I have the Lee manual you speak of. I use it for reference as well as the other 7 or 8 that I have as well as the online data I can gather from reputable sources. When one is way different from the others I have to question that one's results and usually I disregard that one.
That Lee manual tends to run to higher charges than the other manuals I have. Why, I have no idea.
All the references I have are near the 5.0 grain mark.
If you wish to try that heavy charge, I would suggest you work up to it slowly and carefully. Pay attention to all pressure signs and use a chronograph to track your results.
If you are looking for a maximum load, I would suggest you change powders to 296 or H110. 231 isn't going to give you full velocity in that cartridge.
No one manual is the end all for loading. That's why I use several for references.

[freebullet]

Oal can have an impact.