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Discussion Starter · #1 ·
I know load data varies - different test gun, different test equipment, even different temps can come into play but this time the discrepancy is just too big and I am not sure which one to follow:

Cartridge = .41 Mag
C.O.L. = 1.590
Powder = Accurrate #9
Primer = LP
Bullet = 210 gr Hornady XTP

I checked the Western Powder table and the Lee Manual they both agree. Start load = 15.2 (1271 f/s) and max is 16.9 grains for 1445 f/s. However the Hornady manual shows a start load of 15.3 to give 1100 f/s and much more important the max load of 19.2 grains for 1400 f/s.

Why such a great discrepancy? I know to start low and work up, but these are for a Desert Eagle and it does not like light loads. I can work up using the Redhawk, but if two Manuals give max at 16.9, can 19.2 even be safe?

Using same powder for a .357 Mag there is even worse discrepancy -

Bullet = 158 grain Hornady XTP
Powder = Accurate #9
Primer = SPM

Lee and Accurate (western) give a start load of 12.4 and Max load of 13.8 but the Hornady manual has a start of 9.7 and Max of 11.5 which is nearly a full grain under the start load on the other two charts.

Is this problem unique to Accurate 9? This is the first time I wanted to work up a load and found such a great discrepancy. Usually the delta is insignificant and I just choose one of the two start loads and go. But with these 357 XTP loads the start for two sources is greater than the Max for the 3rd source.

Oh yes, will be fired from a Coonan that is pretty low round count so springs have not loosened up yet and I was warned not to use .38 springs until at least 500 357 Mag rounds have been cycled.

My inclination is to follow the recipes that agree but I am concerned Lee may have simply duplicated Western's data without verifying it or vice versa. Any rumor to suggest this has occurred?
 

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I know load data varies - different test gun, different test equipment, even different temps can come into play but this time the discrepancy is just too big and I am not sure which one to follow:

Cartridge = .41 Mag
C.O.L. = 1.590
Powder = Accurrate #9
Primer = LP
Bullet = 210 gr Hornady XTP

I checked the Western Powder table and the Lee Manual they both agree. Start load = 15.2 (1271 f/s) and max is 16.9 grains for 1445 f/s. However the Hornady manual shows a start load of 15.3 to give 1100 f/s and much more important the max load of 19.2 grains for 1400 f/s.

Why such a great discrepancy? I know to start low and work up, but these are for a Desert Eagle and it does not like light loads. I can work up using the Redhawk, but if two Manuals give max at 16.9, can 19.2 even be safe?

Using same powder for a .357 Mag there is even worse discrepancy -

Bullet = 158 grain Hornady XTP
Powder = Accurate #9
Primer = SPM

Lee and Accurate (western) give a start load of 12.4 and Max load of 13.8 but the Hornady manual has a start of 9.7 and Max of 11.5 which is nearly a full grain under the start load on the other two charts.

Is this problem unique to Accurate 9? This is the first time I wanted to work up a load and found such a great discrepancy. Usually the delta is insignificant and I just choose one of the two start loads and go. But with these 357 XTP loads the start for two sources is greater than the Max for the 3rd source.

Oh yes, will be fired from a Coonan that is pretty low round count so springs have not loosened up yet and I was warned not to use .38 springs until at least 500 357 Mag rounds have been cycled.

My inclination is to follow the recipes that agree but I am concerned Lee may have simply duplicated Western's data without verifying it or vice versa. Any rumor to suggest this has occurred?
Go here for information on AA #9, http://www.accuratepowder.com/load-data/
 

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Discussion Starter · #4 ·
Thanks Craver. That is the data I was referring to as Accurate or Western. This data and the Lee are identicle but Hornady data is way different.

When I run into things like that, I use the data from whoever made the bullets, in this case Hornady.

The answer to the main question is probably Lawyers, no offense intended PlanoAttorney.
None taken. I am a family law guy and in my former life I was strictly defense oriented so I agree - it is those greedy Plaintiff's Lawyers again.
 

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Lee doesn't create data, they copy data from other sources while removing helpful information such as components used and barrel length. I don't look in my Lee manual too much because of this.

Studies have shown (as published in the NRA book "Handloading") that a 10% variance in pressure can result from changing a single component such as bullet, case, or primer. Then add lot-to-lot variations in powder and it is easy to see why differences exist.

What I get a laugh out of is load data for Winchester 231 that has a starting charge the same as the max charge of HP-38 (or vice versa). But they are the same powder! Lot-to-lot variation.
 

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Often data varies due to difference in test conditions. One may use an actual firearm to test and another may use a fixed test barrel. 3" / 5" barrel. Most books will list their test setup.
 

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I definitely have to disagree with the lawyer business. That's really not the case. The bottom line is different testing equipment and methods of pressure checking.
As was said, lee doesn't do any testing.

Get yourself a chronograph if you don't have one already and start load development. Once you reach the listed max velocity you're at or exceeding the manuals listed pressure.
 

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Lets say you hae 3 manuals and they all have different data. The bullet isn't made by any of the references. It was suggested to me to pick the reference source in the middle. Also start at 10% below max. I only make one round at that value and test it. If it feels as expected works reasonable, then I start making load work up and go from there. So I take another gun so the shooting time is used since I am there. Try to keep the brass so you can use that to examine as well.
 

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Discussion Starter · #10 ·
Thanks everyone for the info. I suspected but had never confirmed Lee does not test and make it's own data.

Drymag, that is solid advice. I will go out and get a 3rd source today. I am fairly happy with Hornady XTP bullets which is why I bought that manual. I have Hodgon's website save and I downloaded Western Powder's data. Anyone have a recommendation for a third source? Does Lyman create load data or just copy like Lee? What about Sierra?

Get yourself a chronograph if you don't have one already and start load development. Once you reach the listed max velocity you're at or exceeding the manuals listed pressure.
So pressure and velocity are always directly related?
 
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Lyman does their own data, but honestly I don't find myself using it all that often for some reason. I think because their selection of bullets doesn't work very well for me. Hornady is my #1 source for load data, even when shooting plated bullets.

Sierra is a good manual, but it is old and crusty. They seriously need to update it.

So pressure and velocity are always directly related?
I would say that the integral of the pressure curve is more directly related to velocity. The shooter must also be concerned with the peak pressure which may not contribute too much to velocity as it takes pressure over time to cause bullet acceleration. a(t) = F(t)/m
 

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I have a couple manuals and also use the Hodgdon reloading data center online to get a mid-range load. I try NOT to rely on load data gleaned from internet forums simply because anybody can make a typo, though forum info is invaluable to get general reference points and suggestions.

Forum reading is why I settled on Win 231/HP-38 for all my pistol calibers and H-335 for my AR. So far, 7+ yrs and counting, no negatives to report.
 

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Discussion Starter · #13 ·
Hornady is my #1 source for load data, even when shooting plated bullets.
I would say Hornady is also my first source of info mainly because I am using their bullets on most loads - though I have recently acquired Xtreme Bullets for .380 and .45 practice rounds. My only compliant with Hornady is the lack of info. Perhaps the intent was to not burden the reloader with too much info and only publish the top 4 or 5 most accurate or most safe loads. For example, the .357 158gr LRN data does not list anything slower than Accurate #5. Maybe it is fine but I simply do not feel comfortable with a case that is 15-20 filled with powder. It bothers me. I don't particularly know why, but I started to use the Hornady recipe and when I noted the powder was so far down I needed a flashlight to see if there was any powder in the case, I dumped the powder back in the bottle, put everything up and refused to use that load. It may be the most accurate load in the world, but I am not willing to find out. My own personal limit is roughly 50% volume so I can easily tell if there is a double charge and visual inspection is reasonably easy. I have a powder cop but still like to use my Mark II Eyeballs.
 

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WOW! The advice for many years has been start 10% below max and work your way up. Now hear this, 11.5 minus 10% is 10.3 which brings the load in safe with the other manuals. The idea of one round to test for pressure is what I do with rifles. Load one round each to one gr over max and then test to see where I hit pressure. I don't do that with handguns, rather I pick a load several tenth's under max and live with it. I do not use handguns that need to be super accurate and I do not use jacketed bullet's. Even in my 32 long and 38 spec with cast bullet's, I get better accuracy than I require. In my 9mm's, carried only as concealed weapons, all the accuracy I require is to hit a watermelon at 10 yds max. That doesn't require much!

Go back to start 10% low and work your way up. Freshen up on things we'd call pressure signs. They may not be but you stop there and you won't blow up your gun.

I push hot loads from my rifles with jacketed bullet's, case life is five maybe six shots and the primer pocket is getting loose. I shoot moderate loads from my handgun's. Have no idea what case life is but most has been used for years! Early on I destroyed handgun case's, split the necks! Wasn't pressure, rather it was flaring the mouth to much to seat bullet's!
 

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too much info and only publish the top 4 or 5 most accurate or most safe loads. For example, the .357 158gr LRN data does not list anything slower than Accurate #5. Maybe it is fine but I simply do not feel comfortable with a case that is 15-20 filled with powder.
I understand where you are coming from and agree with you up to a point. AA #5 is essentially the same burning rate as Unique but being a ball powder rather than flake it is less bulky than Unique. I have always checked at least 3 data sources for the powder and bullet I am using and arrive at a starting load that is safe in all three sources. Another factor I take into account is the barrel length. If I intend to shoot .357 rounds w/lead bullets primarily in 2" barrels I use Bullseye or AA #2 (or 231 or HP38 if that is all I could get). If it is 4-5" barrels I use Unique or AA #5. Any longer barrel I always use AA #7 or Alliant 2400. Using a slower burning powder than AA #5 with lead bullets just gets you a big flash as the bullet exits the barrel before the powder charge is completely burned. AA #5 and Unique are the powders I would use if I could only have one powder for most handgun calibers.
In the almost 40 years I have been reloading I have loaded untold numbers of .38 Spec HWBC's using the decades old standard target load of 2.7 gr Bullseye. You can hardly see the powder in the case bottom. If you drop this load in a scale pan to weigh you can hardly believe it would even get the bullet out of the barrel, but it does. The main reason I normally like a bulkier powder is it is usually impossible to drop a double charge in most handgun cases, where as with Bullseye or AA #2 great care has to be taken to be sure a double or triple charge hasn't been dropped.
 

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I would say Hornady is also my first source of info mainly because I am using their bullets on most loads - though I have recently acquired Xtreme Bullets for .380 and .45 practice rounds. My only compliant with Hornady is the lack of info. Perhaps the intent was to not burden the reloader with too much info and only publish the top 4 or 5 most accurate or most safe loads. For example, the .357 158gr LRN data does not list anything slower than Accurate #5. Maybe it is fine but I simply do not feel comfortable with a case that is 15-20 filled with powder. It bothers me. I don't particularly know why, but I started to use the Hornady recipe and when I noted the powder was so far down I needed a flashlight to see if there was any powder in the case, I dumped the powder back in the bottle, put everything up and refused to use that load. It may be the most accurate load in the world, but I am not willing to find out. My own personal limit is roughly 50% volume so I can easily tell if there is a double charge and visual inspection is reasonably easy. I have a powder cop but still like to use my Mark II Eyeballs.
I use AA powders almost exclusively. If you go to their web site you can order a free book on reloading their powders. It's in magazine form. You can also print out the info that's on line. I also like the Hornady bullets, and most of my reloads for hunting, or SD, are Hornady XTP's. For practice I usually load my own cast bullets. I use three manuals to choose my load, Hornady, AA, and Sierra. I will also use the Lyman manual too. I shoot a lot of the #2, and the #5. My method of reloading prevents any possible chance of a double load. Still I have a light right above my work space that allows me to look into any, and all, cases in the reloading block.
 

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Discussion Starter · #18 ·
My method of reloading prevents any possible chance of a double load. Still I have a light right above my work space that allows me to look into any, and all, cases in the reloading block.
I have a powder cop die but have not used it - I am looking in the case as you suggest but get really disconcerted when the powder fill is so low that it is difficult to see too much powder. I don't have the numbers in front of me but I think several sources had ~5gr of powder if using a fast burning powder in a 357 Mag case. It is not a worry the bullet will not leave the barrel; the thought in the back of my mind is if the powder will even ignite and more important the powder level is so low I don't trust my own visual inspection during reloading. The first problem is likely just in my head and can be solved by simply firing several rounds, but the second problem . . . . well, it is just easier to solve with a slower powder.

Slower powder (higher fill) just "feels" better and it does not hurt I am firing them from a Coonan with a 5" barrel so slower powder should be fine.
 

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I run into this issue at work daily and it is extremely frustrating. there are a ton of variables I've noticed that affect the velocities even though I use the same, gun, powder, projectiles, shells, range, chronograph, ect. I've just started to track for my own curiosity how the weather affects the data. although i haven't tracked a bunch of data yet I've noticed that the colder outside it is the slower my the velocities even though the rounds are made in a climate controlled building. By up to 50 fps and I'm only dealing with rounds that go around 250 fps. If I clean the barrel and it still has some CLP in it it shoots faster than if i clean and dry the barrel. How high or low the crimp/seat is changes it also. The machine I use can be running the rounds perfectly one day and the next morning I will have to change amount powder.
This is a great thread and the main reason I joined to see what more experienced people have to say
 
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