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

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..

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.

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.

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.

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.

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.

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!

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

__________________
Freedom is never free!!
SWCA #3437

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

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

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.

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.

__________________
Freedom is never free!!
SWCA #3437

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.

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.

__________________
Freedom is never free!!
SWCA #3437

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

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.

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.

__________________
Freedom is never free!!
SWCA #3437

I'm not much of a believer in expansion in the first place, but if you're operating that close to the edge of a bullet working/not working, I'd say you probably shouldn't use that load for anything important.

Even manufacturers data can be misleading from lot to lot Some time ago I decided to go to Tightgroup powder as a multi-caliber option (38 Special/44.40 and .45 ACP). With the .45 I shoot 200 gn jacketed truncated cone (similar to a SWC) projectile out of my Springfield 1911 A1.

The Hodgson site lists two 200 gn loads for Tightgroup in .45 ACP, 5.2 gn max with a Speer JHP for 884 fps and 5.4 gn for 957 fps with a LSWC. As I only needed 850 fps to make power factor (870 for a safety margins) I settled on a 5.1 gn load. Across the chrono it made PF but during a comp recently my loads, from a new batch of three cans of powder I bought after initial load development, failed to make PF and I ended up shooting 45 minor for the weekend.

Afterwards I set about working up a load that made PF and ended up at 5.8 gn to make PF with a slight safety margins. Even 5.6 gn failed to reach 850 fps. There is no noticing each increase in recoil, extraction is fine, cases are not overly expanded and POA/POI is the same as previously.

So now every time I buy powder the first thing I do is load 20 or so rounds using the previous powder lots' data and head for the chrono.

Lead bullets

I use Lyman's loading data. The starting to a mid-range powder charge will be a safe load. Bullet weight ± 10% is close enough for that starting load. Load data for a heavier bullet will be safe for a lighter bullet.

Jacketed bullets

I use the bullet manufacture's load data if I have the listed powders. When I have suitable powder that is not listed by the bullet manufacturer, the powder manufacturer's load data will give you a starting load based on jacketed bullet weight. Again, at a starting to mid-range load, bullet weight is close enough to safely load. Some bullet manufacturers lump load data for bullet weight together. For example a 150 grain weight bullet, the FMJ, round nose, soft point, spire point, and hollow point bullet all use the same powder charge data. Separate cartridge overall length is listed for each bullet.

Maximum powder charges

Once a mid-range load is tested, the powder charge can be increased in 2% or 0.5 grain intervals and fired for accuracy, pressure signs, and velocity. A chronograph is important for max load development. Shooting several boxes of mid-range loads before doing max load development is prudent. Starting loads are safer and far more forgiving than max loads for the new reloader.

__________________
S&WHF 366

That is why reloading is a challenging Hobby...........

I hate it when data does not show the length of barrel or weapon used.
I also double hate it when I see a "Universal barrel listing.

I also do not care for Hodgdon's pistol/Revolver data with the use of a 7" barrel.
Who shoots a 7" 38 snub nose or a concealed pistol, in these modern times ?

Another reason that this site is so GREAT !!

And when I get close to the top end load,I like to increase the charge only in 0.2gr increments.I've found that developping a load during wintertime when the temperature is in the '30s will raise its pressure in a measurable way when said loads are shot during summertime in the high '80s.
In the case of my favorite caliber(.44Mag),it makes the difference between nice vs flattened primers.It should be even more significant in the case of smaller calibers(i.e..357Mag).
Qc

Probably not - different guns give different results.
Same with different lots of powder, etc.

Lee data is nothing more than a compilation of data from the various powder manufacturers. That load is from Hodgdon. See attached pic.

Hope this helps.

Untitled.jpg

__________________
an actual conservative

Also need to look at OAL. This effects pressure and max load.

__________________
Beware the man with one gun.

Lee copies date for their manual from other sources, they don't perform any pressure testing.

I find sticky extraction at 40 grains with this bullet powder combination. For the OCD I crimp at the top of the cannalure .
This bullets expand to about 3/4" at velocities over 2000 fps.

You will find this combo suitable for hunting Deer and pigs.

be safe
Ruggy