# contradicting load data?



## Mr.CheddarNut (Jan 16, 2013)

What do you do when there is signifigant difference in load data. 

For example: 308 winchester

Hornady says for the 178gn. Amax, max grains of IMR4895 is 41.1grains
RL 15 is 41.4grains
Lee manual says max IMR4895 for 180 jacketed bullet is 44.7
RL 15 is 45

Seems like quite the spread, about 8% Any thoughts?

Cheddar


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## silentstalker (Feb 19, 2008)

Load data is very generic and based on safety margins. Always start well below max and work up to your rifles max. All rifles are different. You may get to max with pressure signs well below the book max. With my rifles, I have found max to be a grain or two above the book. Your rifle will tell you when your approaching max. Flattened primers, difficult bolt lift, to name a few signs. 

What versions of each book are you using. The lawyers have made companies lower max seemingly across the board to be safe. The older books list higher max charges.


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## Mr.CheddarNut (Jan 16, 2013)

silentstalker said:


> Load data is very generic and based on safety margins. Always start well below max and work up to your rifles max. All rifles are different. You may get to max with pressure signs well below the book max. With my rifles, I have found max to be a grain or two above the book. Your rifle will tell you when your approaching max. Flattened primers, difficult bolt lift, to name a few signs.
> 
> What versions of each book are you using. The lawyers have made companies lower max seemingly across the board to be safe. The older books list higher max charges.


The Lee is Modern Reloading Second Addition
Not sure on the Hornady as it was a photo of the pages from a fellow forum member. I suspect within 2yrs old.

Cheddar


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## DallanC (Jan 13, 2009)

Wait till you start comparing load data from older manuals with more recent data. Specifically I have 7STW info from the same mfg that over the years has changed by a tremendous amount.


-DallanC


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## Mr.CheddarNut (Jan 16, 2013)

Off topic but I am having some serious difficulty sizing some 25-06 this evening. They are super tight and just wont cooperate. Am I doing something wrong? More lube? Less lube?

Cheddar


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## silentstalker (Feb 19, 2008)

I use the spray lube and apply it liberally. You should not have too much difficulty. Is this the first time using this sizing die? Make sure its set up correctly (according the the manufactures suggestions) and apply the lube. Also make sure it will chamber in your rifle before you load the brass up.


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## Loke (Sep 7, 2007)

Load data has changed over the years, not because of lawyers, but because of advances in pressure measuring equipment. Bullet construction will also affect pressures. A bullet with a stiffer jacket and harder core takes more effort to deform to the riflings than a softer bullet. A generic soft point might also have a smaller diameter than a match bullet. This will also affect pressures. Modern powders might also have more energy per grain than their older counterparts, even if they have the same burning rates. This will also affect pressures. Unless you have modern piezo-electric pressure measuring equipment, the most reliable way to guestimate pressures is a chronograph. If your velocities are in line with the manuals, your pressures are most likely similar. This only applies if your rifle has the same barrel length as the test model. And even then, don't go past the maximum loads in the book.


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## KineKilla (Jan 28, 2011)

I've wondered the same thing.

The most recent Nosler manual (#7) says 59.0 - 63.0gr of IMR 4831 is the spread for my 7mm RM

But the IMR website says it is 57-61 so exactly 2 grains shorter top and bottom.

I'd like to start at the bottom and work up as is always suggested but when you don't know where the bottom is....?


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## DallanC (Jan 13, 2009)

+1 what Loke said.

Really, everyone should be starting off well between min and max anyway and safely working up the load for their own rifle. I'll admit to googling up a load for a new caliber off forums, and seeing if there is a general consensus alot of people agree to (that is still within min/max), but even then I'll load up 5 round batches starting off a little light and working up to the target load. The most popular 7mm08 load I found on the reloading forums actually turned out to be spot on for my boys gun, still within safe limits and dead accurate.

PS: On loading that 25-06 are you lightly lubing the inside of the case mouth?


-DallanC


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## Loke (Sep 7, 2007)

KineKilla said:


> I've wondered the same thing.
> 
> The most recent Nosler manual (#7) says 59.0 - 63.0gr of IMR 4831 is the spread for my 7mm RM
> 
> ...


Check the spec on the test rifle. I'll bet one is a minimum spec test gun and the other is a production rifle. The 7mm Remington magnum is notorious for having generous chamber specs in production guns. Also the difference in bullets can have a huge impact on pressures. A high BC boat tail bullet and a round nosed flat based bullet of the same weight will have a significantly different bearing surfaces. This will affect the friction of the bullet in the bore, which will affect pressures. Use data for the bullet you are using, especially if it is of a different construction.


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## Mr.CheddarNut (Jan 16, 2013)

DallanC said:


> +1 what Loke said.
> 
> Really, everyone should be starting off well between min and max anyway and safely working up the load for their own rifle. I'll admit to googling up a load for a new caliber off forums, and seeing if there is a general consensus alot of people agree to (that is still within min/max), but even then I'll load up 5 round batches starting off a little light and working up to the target load. The most popular 7mm08 load I found on the reloading forums actually turned out to be spot on for my boys gun, still within safe limits and dead accurate.
> 
> ...


Yes. I think the inside of the sizing die is gunked up with stuff. Bringing the ram back down the casing would have some different colored marks of something on it, and on occasion a flake of I presume dried lube/wax substance would fall out. I am going to try and clean it, blow it out and then get some _spray type_ lube and try again.

Cheddar


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