Conflicting 308 load data

[ldlfh7]

The load is for 308 winchester with 125 gr sierra sp and IMR 4895.
I am just wanting to confirm the Hogdon load from their website is correct with the minimum being 48 grains and max at 51.3 grains.

I am double checking this information because Sierra lists the same load in their 5th edition with the same components with the min at 42.5 grains and max at 46.2 grains. I called Sierra and he said that IMR 4895 can be easily reduced without much of an issue but I expressed concern with the max Sierra load was listed below the minimum Hogdon load.

I understand different cases have different capacities which could cause some load variation but this is quite a difference.

Hogdon said I could use their data with no issues. How can there be such a difference here? What the heck should I do?

I would really like to use these loads for deer season this year and moving at least 3000 fps.

Any help is greatly appreciated.

 

[steve4102]

Lyman lists 43-47gr.

Hornady lists 41-49.4gr with 130gr bullet.

Start at 43ish and work up.

OH, BTW, Sierra data is not pressure tested data. They test their loads in regular rifles and read brass cases to determine pressures. In other words , "They Guess".

 

[rodregier]

Hornady is an ammunition manufacturer, the others are not.

As such, Hornady probably has an instrumented universal receiver for testing loadings. If it was a recent Hornady manual, my nod would go to them if you're making a choice.

The other general issue (as noted in any of the good reloading manuals) is that each load is developed with a specific firearm (or receiver barrel), die set, projectiles, brass, propellant and primers. Setup by the technican for the dies is also a variable too.

That all adds up to a lot of variables which can also account for some of the differences between manuals.
That is one of the reasons the good manuals all advise - start low, work up.

 

[USSR]

...Sierra data is not pressure tested data. They test their loads in regular rifles and read brass cases to determine pressures. In other words , "They Guess".

True! I called them several years ago regarding a "Max" load and the amount of pressure associated with it, and they said "that's just where we decided to stop". Aside from that, Hodgdon used Winchester brass which is the lightest with the most case capacity. Brass used in .308 Winchester is critical in load development. I agree with steve4102. start at about 43 grains and work up from there.

Don

 

[rcmodel]

Hornady probably has an instrumented universal receiver for testing loadings.

So does Hodgdon.

They have used a Universal-Bond pressure test gun for at least 50 years.
That's how C.U.P was measured in all their data.

They now use electronic pressure test equipment.
That's how their P.S.I. date is measured now.

rc

 

[steve4102]

Hornady does have pressure barrels for most cartridges, but not all. Page 74 of Hornady #7 explains, if pressure barrels were not available the used regular firearms, read the brass case and guessed just like Sierra does.

Hodgdon, Accurate, Ramshot, Lyman all list tested pressures, I trust these manuals before those that do not list pressures.

 

[ldlfh7]

Thanks for the answers everyone. I guess I will work with the data in my 49th Lyman. 43-47 grains. Using LC brass I will probably work my way from 43 to 45 or 45.5 or so. Looking forward to see what this fast moving 30 cal bullet does to whitetail in a couple weeks!!