new lot of H-4831

[bob4]

So when it's time to open a new can of H-4831 and you're loading close to the max for say a 270, do you drop back 10% or just a couple/few grains and shoot a couple of each working back up ?
I've read Hodgdons claims of barely a difference from lot to lot and also have seen a test that says otherwise.

 

[Barrelnut]

I would drop back 5% and see what ya got. I recently switched to a new lot of H4350. The new lot was slower. I had to add 5% more powder to get back up to speed and on the node. It probably could have just as easily gone the other way.

IMR told me they keep new lots within 3% and usually the spread is more like 1~1.5%. I think this is an industry standard. But seems I've seen it worse than that.

I started a new lot of H1000 yesterday and I could barely tell the difference from the previous lot. Seems the new lot was running 20 FPS or so faster.

And or course, if you have a powder you use frequently, buy all the 8 pounders on the shelf.

 

[MagnumManiac]

Agree with Barrelnut.
I worked for ADI here in Australia making all Hodgdon stick powders, and yes, the standard that must be adhered to for canister powders is to be within 3% of the burn rate, otherwise it gets blended for commercial use.
I drop down 5% from the max load when switching lots, but, often, there is no need.
I buy my powders in large lots to avoid problems, but, even then I will blend old lots with new lots if a can only contains a 1/3 or less of powder.
Never had a problem doing this in even 1 pound containers.

Cheers.
gun)