Lyman load data VS. Lee load data

[ferggie]

I was a a bit surprised when I compared load data between my 49th ed Lyman reloading manual and my 2nd ed Lee Modern Reloading manual for S&W460 load data.

Lyman: Barnes XPB 250 gr., H110 powder
Starting : 36.5gn Max: 38.5gn
1985 fps 2123 fps

Lee: Barnes XPB 250 gr., H110 powder
Starting : 39.0gn Max: 41.5gn
1985 fps 2133 fps

I am a little spooked when I see one starting out above the max recommended load of another source. I would greatly appreciate any help regarding this issue since this is not a round I want to risk an excessive load on. (none for that matter)
Thanks

 

[stumper]

The I have older versions of the Speer and Hornady books and the differences between those two is also huge. Speer is consistently showing much higher maximums than Hornady on all calibers. It does make it frustrating trying to figure out where to start with a load. You would think they could standardize a bit better..

 

[ferggie]

The pressures generated by this round are high as is with safe loads and I sure don't want to go above max loads by that much if it isn't safe.

 

[mkk41]

Different sources have different test conditions , test equipment , powder lots , primers , all will give variations in pressure and velocity. That is why almost all reloading sources recommend starting at 10% below max when using new componants of developing a new load.

 

[125JHP]

My 2009 printing of the Modern Reloading Lee 2nd Edition doesn't list the 460 S&W so you must have a newer edition.

One problem with the Lee manual is they don't give a lot of necessary data to evaluate their load recommendation. They only list a Minimum OAL, for all the good that does, and not the actual OAL of the tested load. They also don't seem to mention test barrel type or length, case or primer used. Notice also that pressures are listed in CUP, PSI and N/A. I'm pretty sure they don't pressure test anything and just use whatever is listed in their original data source, but they don't list their source of the data.

I have heard that the Lee book is just a compilation of various manufacturer load data, collected in one volume but with a lot of necessary data left out for formatting sake to include their load disk info.
Sure that book is useful if you use Lee powder measuring equipment, but for all other uses, for me, it's just a cursory additional source to verify other load data sources. In other words, I take that book with a grain of salt unless it agrees with what I have found elsewhere.

I have the Lyman #48 so once again I can't look at the 460 S&W data. Comparing the two, the Lyman book appears to be much more detailed in any given info they provide and I would tend to believe Lyman more if I had to make a choice,however they too can be way off from other reputable sources.

When I see a big difference in data, the first things I check are the OAL and the shank length of each bullet they used for their load. You could always load up 3 at the lowest starting load and then increment your way up.

One thing that looks suspicious is that you listed the exact same velocity for both loads... is that correct or a typo? If correct then one of those loads is highly suspect.

 

[Aticus]

The Lee book is a compilation of other's load data. Lyman tests their data and give you the equipment data.

In recent years most of the published data has shown reduced powder charges over all. This is due, primarily, to a change in how the pressures are measured. In years past cartridge pressures were measured using small copper or lead cylinders that were measured and compared to pressure tables provided by the cylinder manufacturer. Hence the terms copper units of pressure (CUP) and lead units of pressure (LUP). Now most of those measurements are done using electronic means reading directly in pounds per square inch (PSI). Ballisticians found that some of the charges they were advocating as safe were well over the SAAMI specs for a lot of cartridges, thus the changes. Lee has apparently not caught up with these changes.

Bottom line I'll trust Lyman before I'll trust Lee. Do what you please it's your gun and your hand.

 

[shootnduck]

I have the Lyman 48 edition and the data provided for 44 special and the actual chronographed data is different. To me that just reinforces the need for a chrony if one can afford them.

 

[mkk41]

Bottom line I'll trust Lyman before I'll trust Lee. Do what you please it's your gun and your hand.

I don't use Lee molds so I don't use their data. BUT , as I stated above , due to differences in design , data for the mold should be used.

We've used this pic before.

The bullets in the middle are of similar weight. But data for the 220gr Lyman 'Keith-style' SWC (center-left) will show a higher max load than 215 SWC-BB one (center-right) which will compress the powder charge.

Another example is that the 220gr Lyman #410459 has a max load of 20.1grs of 2400 for 35,4000 CUP while a 215gr SWC #410610 with much longer shank has a max of 18.8grs for 37,000 CUP

And while 2400 does like a compressed load , not THAT compressed.

And faster burining powders like it even less!

 

[ArchAngelCD]

Lyman: Barnes XPB 250 gr., H110 powder
Starting : 36.5gn Max: 38.5gn
1985 fps 2123 fps

Lee: Barnes XPB 250 gr., H110 powder
Starting : 39.0gn Max: 41.5gn
1985 fps 2133 fps

Did you make a mistake with the velocity data? They are identical so I'm guessing you re-wrote the same numbers by mistake.

 

[mkk41]

I have the Lyman 48 edition and the data provided for 44 special and the actual chronographed data is different. To me that just reinforces the need for a chrony if one can afford them.

Velocity and pressure are two different animals. Higher pressure does not always equal higher velocity and vice-versa.

 

[rockquarry]

Best to use the compiled Lee data for comparison / reference purposes only, not for actual loading recipes.

 

[Skip Sackett]

Lyman data can be just as wrong and any other and is wrong unless you use their EXACT same data and components.

EVERYONE'S data is like that, by the way.

Personally, after a bad experience with Clays and Lyman data I started using the POWDER COMPANY'S DATA FIRST!

That would be my suggestion to all of you. Put the Hornady book down, the Speer book down, the Lee book down and go to the folks that made the powder. The data is free for the most part, and, available on the web. Win/win in my book. Then, if you want to venture into other territory, go to the published data from other sources.

For the last 15 years or so, that has been my approach to what data to use first. I had one incident before I started using that "theory" and none since.

Take it or leave it.

 

[ArchAngelCD]

I agree with Skip, I always check the powder and bullet manufactures data before i load anything. Also, much of the Lyman data has been reprinted for decades and not retested so it can also be faulty. Their new data is actually tested by them as was the older data but the older stuff is still old.

 

[Skip Sackett]

Here is Hodgdon's data:

250 GR. BAR X
Hodgdon H110
Bullet size .451"
OAL 2.200"
Starting grains 39.0 1985fps 43,500 PSI
Maximum grains 41.5 2133 56,800 PSI

Just to muddy the waters a little more.

 

[mkk41]

I agree with Skip, I always check the powder and bullet manufactures data before i load anything. Also, much of the Lyman data has been reprinted for decades and not retested so it can also be faulty. Their new data is actually tested by them as was the older data but the older stuff is still old.

Great point. Keep in mind powder manufacture is not EXACT. It's darn close , but powder burn rates can vary significantly from lot to lot. I've always heard "some lots are faster/alower" for as long as I've been loading.

And powder 'lots' are manufactured by the ton or more.

 

[ArchAngelCD]

Great point. Keep in mind powder manufacture is not EXACT. It's darn close , but powder burn rates can vary significantly from lot to lot. I've always heard "some lots are faster/alower" for as long as I've been loading.

And powder 'lots' are manufactured by the ton or more.

True, no data can be exact and the rule holds true there to, unless you're using the same exact components the pressures and velocities will be different.

 

[ferggie]

Sorry

Did you make a mistake with the velocity data? They are identical so I'm guessing you re-wrote the same numbers by mistake.

You are correct. The Lyman was 2016 fps - 2123 fps.

 

[mkk41]

It all boils down to three little words we stressed in the Navy and in the machine trades,

"ATTENTION TO DETAIL!"

Once ya start thinking that "this doesn't matter" or "that doesn't matter" or "it's all the same" , is when ya get bit.

 

[cp1969]

All the more reason to stay away from top loads. They rarely gain you anything, that last 100-200 fps makes little to no difference to target, trajectory, man or beast.

 

[ArchAngelCD]

All the more reason to stay away from top loads. They rarely gain you anything, that last 100-200 fps makes little to no difference to target, trajectory, man or beast.

That's not always true. Sometimes that 100-200 fps makes the difference between reliable expansion of the bullet or not. But, if it's just for the additional velocity alone, then you are correct, it means nothing.