Who's reloading data to trust, Lee or Lyman?

[inline50]

I am reloading for my new 40 cal. and I have the new Lyman handbook with grains starting from 4.9 to 5.6 max. If I use the Lee paper included in my die set, the starting is 5.9 to 6.7 max using Unique powder. Since the starting limit from Lee is over the max. limit given from Lyman, who should I believe? Am I safe staying under the 6.7 given by Lee. I was going to use 6.4 grains. Any Ideas?

[ShooterAZ]

Personally, I would trust the Lyman data over Lee. Also, please work up to max loads...don't start with them.

[sidecarmike]

How heavy a bullet? Alliant, (Unique) recommends 8 grains for a 155gr slug and 6.7 grains for a 180gr.
When in doubt, I usually go to the guys that made the powder I'm using.

[shooter93]

If you start with the Lyman you could work up to the Lee if needed. If you start with the Lee and it's to much....you don't get to go back to the Lyman....smiles.

[jmort]

Alliant has 6.7 max with 180 grain jacketed bullet. Lee data will be closer to Alliant data. I will trust the manufacturer over non- manufacturer data.

[runfiverun]

lee just re-prints other peoples data.
if you wanna use the lee data ask yourself a couple of questions first.
1 what brand of bullet was used?
2 what brand of case was used?
3 what brand of primer was used?

if lee shows the entire recipe, I'd feel a lot more comfortable working with it.

[Hickok]

Out of my Sig P229 .40 S&W 5.5 gr Unique and Lee 170 gr. boolit =947 fps

[country gent]

I always check 3 or 4 data sources to see what they all recomend. One thing I like about the one caliber data books, They have lyman sierra speer powder manufaturers data and bullet makers data all in one place. Allows me to judge what is what. Many things affect what is a safe load, case, primer, bullet wieght / type, Barrel dimensions, chamber, and throat all have a bearing on pressures.

[fryboy]

i dont trust anyone's data - until i work up safely to it

for one thing i have my very own chamber
i also have my own reloading techniques
my own overall length
and a different lot of my own components

that start small and work up safely is mentioned in every single reloading manual i have ever read
what you do of course is up to you , but for a qualifier i've often found a most accurate load long before i've reached max in my particular circumstances ( see that " my own" list above )

[Duckdog]

Heck, I've seen Lyman differ considerably between editions on the same bullet. I just bought their latest shotshell manual and it is a bunch of recycled ****, so, I would not hesitate to trust the Lee data because they also just recycle info. The Lyman manuals used to be a lot better and had loads that were sometimes hotter than the powder manufacturers data, but they must have been bitten in the **** by the liability bug as well.

[fredj338]

You do not "trust" any of them, they are guide lines for YOUR individual gun & components. When working with a new caliber or powder/bullet combo, I will use 3 sources & avg the data for starting, mid & max, then work the load up using avg max data & on 1/10gr increments for faster powders in handguns, 3/10gr in rifles.

[singleshot]

Start low and work up.

In addition, it's HIGHLY unlikely the data uses the same components AND same OAL...so the answer may be they're both right.

[Animal]

The load data you read in a published manual is just a detailed journal of what works in their testing environment, equipment and supplies; not your gun. They do a good dang job of figuring out basic parameters that will work in properly manufactured firearms. That is it. Nothing more. It doesn't sound like much, but it is a hell of a lot better than guessing.

Lee can complicate things because he doesn't like calling out which bullets he uses. Sometimes he won't even list a minimum load. Look at as many reputable sources that you can find and ask questions... lots of questions.

[codgerville@zianet.com]

personally, i would trust the lyman data over lee. Also, please work up to max loads...don't start with them.

amen!

[sidecarmike]

<SNIP>. Sometimes he won't even list a minimum load. Look at as many reputable sources that you can find and ask questions... lots of questions.
I'm seeing this a lot lately. I was looking for some 44-40 loads today and found that even many of the powder manufacturers are only listing a max load. That frightens me. Too many people these days don't read the fine print. I'm getting ready to load for an ancient Colt SAA. The last thing I want to do is blow up the gun.

http://www.alliantpowder.com/reloaders/recipedetail.aspx?gtypeid=1&weight=110&shellid=26&bulletid=31

[mpbarry1]

start low and work up. look for pressure signs, and use caution. I will say that the manufacturers have gotten very conservative with max loads lately. Which doesn't bother me much because I rarely approach a max load.

[dragon813gt]

Lee can complicate things because he doesn't like calling out which bullets he uses. Sometimes he won't even list a minimum load.

Lee doesn't perform any testing. They only reprint data from the manufacturers. So if no starting load is listed, the manufacturer didn't print one either. You will see this currently on Hodgdon's site. They will also tell you that when no starting charge is listed you back off the max charge 10% and work back up. The monkey wrench is with certain powders that can't be downloaded that far. Which aren't noted in books like Lee's.

If you want data for the components you have call the powder or bullet manufacturer for it. They will at least give you the data for the components and powder they used.

[mikeym1a]

I just checked the Lyman Reloading Manual, 49th edition. The loads that the OP lists is for the 180gr jacket bullet. The load he mentions in the OP from Lee corresponds with the load for the 135gr bullet - 5.8gr - 6.8gr Unique. It's been a while since I looked at anything included with loading dies, but, if they gave this load, they would have been smart enough to list a bullet weight. I the OP needs another source, the Hodgdon has their own site where you can look it up; http://www.hodgdonreloading.com/. I have 6 different manuals to look at and compare. Perhaps you should start shopping around, and get some old copies of different manuals. It could be of some assistance to you. mikey

[Cmm_3940]

As others have said, Lee just reprints the powder manufacturers' Data. It's a convienient compilation of sources, but is not a data source in and of itself.

Lyman doesn't make bullets or powder, so might be considered impartial, but their data tends to be way hotter than, say, Hornady.

So who do you trust? As others have already said, NO ONE.

Personally, I gather as many sources as I can. I rarely shoot the exact bullet listed in any data book, So I look for similar designs in the same grain weight from many sources. Once I choose a powder and bullet, I get the min and max from as many as I can of Sierra, Hornady, Speer, Lyman, Nosler, and the powder mfg. I then take the average of all the relevant start loads, and the average of all relevant max loads and use the results as a sort of 'consensus' data set.

But that's just me. I do this to save a bit of $$ in components working up a load. To be the most safe, you should take the far spread of all data sources, and start from the lowest start load.

[jonp]

I'd start on the low end and work up until I found an accurate load then stop. There is rarely if ever a need to go to max on anything and I have never encountered a max load that was the most accurate.

[Hickok]

Out of my Sig P229 .40 S&W 5.5 gr Unique and Lee 170 gr. boolit =947 fpsInline do as these fellows suggest and start low and work up. I put my load here to give you an idea of what Unigue and a 170 cast boolit would do in my handgun. Don't trust my data either, there are too many variables. Sorry I didn't caution you, and I apologize.

These small high pressure handgun rounds can be touchy to small increases of powder charges and boolit seating depth, different primers and cases.

[Randy C]

Inline start low and your way work up. They have given you good advice here. That's why I very seldom post any where else. I used Shooting times Form but its gone now.

I have almost every manufactures book and the Internet, I remember the first time I did not. Some one here caught it, I was shooting my 308 with Berger 168gr VLD I used the info for something like a Nosler 168gr and I was close to max charge trying to see how much powder was going to be my best load. My neighbor was next to me and he was shooting his 7mm and he likes it hot it was loud, he looked at me and said are you still shooting a 308 dam that thing is loud it was throwing the brass hard and it had a larger then normal dent in it, primers looked good. Berger did not have a book out then. The VLD is a lot longer bullet and takes less powder,I was compressing a dangerous load Its a good thing I was shooting a well built Browning a lesser rifle could of hurt me.

I cast most calibers and use a Corbin press for my 243 there is a lot of variables in my bullets compared to factory bullet / data and weaker guns. Do your home work and wear your safety gear when shooting especially reloads.

I have never stopped learning what's safe and look forward to upgrading my skills here.

[canyon-ghost]

Trust the reloading data in your own notebook! Consider twist rates- I have old and new 9mms with differing twist rates. The newer ones develop more pressure quicker, the older one shoots anything with almost twice the length of twist. Just start with a low starting load and work up to what suits your use.

[William Yanda]

"When in doubt, I usually go to the guys that made the powder I'm using."

Sounds like a plan to me.

[mdi]

Personally, I would trust the Lyman data over Lee. Also, please work up to max loads...don't start with them.
I agree...

[Old School Big Bore]

The first thing is to know your bullet weight. You don't state it and there are .40 projectiles from <100 gr to >200 gr. The next thing is to understand that whoever worked up whatever data you're looking at used THEIR gun, brass, primers & dies, and that all those variables mean that any published data is APPROXIMATE. Starting loads are called that for a reason. Load a few at the lower end, see how they do, step up til you get functioning.

[dbosman]

I trust the powder manufactures data. It's online too.

[blikseme300]

"When in doubt, I usually go to the guys that made the powder I'm using."

Sounds like a plan to me.

This is what I do. Neither Lee nor Lyman manufacture powder and they merely publish numbers that they got from the manufacturers. Go to the source of the powder for numbers and not the people that make the tools.

[TXGunNut]

I think this thread reinforces why I have several loading manuals and spring for an update on a regular basis. I wish more manuals addressed the reduced loads that I like for cast boolits; Lyman does a good job but they're a bit too conservative sometimes. I like Lee's new format but he generally doesn't list the powders I like and I'd like a bit more info on the bullets and primers used but there's simply no room. I like the powder sites but Alliant sometimes doesn't list the powders I know will work. The Hodgdon site usually goes a lot faster than i want to go and their max loads are often well over what I'm comfortable loading.
In short, no one manual should be trusted or relied upon completely. I consult several sources before I sit down at the loading bench to load a cartridge for the first time and I'm working harder to keep better notes because as mentioned above they are the only loads we can truly trust.

[Duckdog]

I personally find the Lee 2nd edition to be a good resource for reduced loads. If you do not use the listed powders in his new BHN vs pressure formulas, you can always go back to his reduced load calculations for any powder. I can't remember it off hand, but it does work pretty good to get you going. I do not load my cast bullet loads so hot that a primer will put me over pressure, so primers are the least of my considerations when working up a load. Everyone is dead on in that no one reference is the definitive source of information.

[gray wolf]

Consensus is start low and work up if any doubt is present at all.
I also find the Lyman data to lean to the conservative side.
But I must say that in the past it seemed that most data was somewhat in line with each other.
Now I find that not to be so. Yes we have discussed some of the reasons for this.
But I am starting to realize more and more the importance of a Chronograph.

[Boogieman]

This is what I do. Neither Lee nor Lyman manufacture powder and they merely publish numbers that they got from the manufacturers. Go to the source of the powder for numbers and not the people that make the tools.

I agree on using the powder mfg data to start. Lyman has a test lab for load development .Lee 's were done on a computer or came from other sources. Rule#1 start Low & go up SLOW.#2 read the whole book FIRST. The powder mfg's have good about answering my questions on the phone.

[fatnhappy]

The answer: Don't.

Don't trust the data from either. Scour the manuals of all the powder and bullet manufacturers and weigh the general consensus of multiple sources. Scrutinize and vet your data. Typos happen. Trusting a single data source is like trusting NBC news.

BTW, you don't necessarily need to spring for multiple manuals either. Using the internet or your library should suffice.