variation in powder lots?


April 6, 2013, 05:51 PM
So recently I've been working up a load for my 338 win mag. I've finally found the powder(imr 4831)and charge(68.8 gr) that it likes with the 225 accubonds. My problem is I don't have enough powder left to load rounds for elk season. The gun is pretty finicky, I have quite a bit of time and components (accubonds aren't cheap) into this already. How much of a difference do u guys think a different lot of imr 4831 will make? You think I'll need to do some more testing when I find more powder?

If you enjoyed reading about "variation in powder lots?" here in archive, you'll LOVE our community. Come join today for the full version!
April 6, 2013, 06:54 PM
Its really just to identify powder at the factory and how much they produce. I've bought powder in 2 different lot numbers all the time, never had a problem with them. When you get a new pound of it just make 1 or 2 test rounds and if you chrono your rounds, chrono it. I don't chrono my rounds, I used to but then chrono broke, so from my old load data I just go from that.

You should be fine with a new lot of powder, if your worried about it, get a few pounds then you have extra down the road to fall back on.

April 6, 2013, 07:03 PM
I called Accurate Arms once and they told me that the industry standard for powders was 10% per lot, but Accurate Arms held their tolerance to 5%.

You probably won't have a problem with a midrange load, but a maximum load, anything can happen. :uhoh:

April 6, 2013, 09:37 PM
Thanks for the replies, I kinda figured it shouldn't be too much of difference, but with this gun .2 grains seem to make a difference.I'll load and shoot a few when I get the powder and make sure.

April 6, 2013, 10:25 PM
As stated, powder lots are meaningless unless you have to contact the manufacture with a problem and need to refer to the lot number to see if there is a known problem with that lot number.

In the real world?

Canister powder sold for reloading is so exactly the same from lot to lot you don't even need to consider it a factor unless you bought your last lot of WWII surplus H-4831 from Hodgdon in 1953, and your current commercially made H-4831 last week.


You got bigger fish to fry with your reloads then matching powder lot numbers.

If there was really a 5 - 10% variation between lot numbers of the same powder?
There would be different pressure tested reloading data for each lot number of the same powder!

But there isn't.

5 - 10% is sometimes more then the difference between two completely different powder numbers.


If you enjoyed reading about "variation in powder lots?" here in archive, you'll LOVE our community. Come join today for the full version!