mixing different lots of same powder

[porthos]

as the title says: just bought the last bottle of IMR 4198 at a local store. i have i and a half CANS of the same . probably about 30 years old. my question is . can i mix all of it together without any ill effects? it will be used in low doses for cast bullets. and then it will all be the same mix. many years ago i mixed ball-c and ball-c2 together. probably wasn't smart, but i started with a lower dose and worked up. everything was ok.

[Winger Ed.]

If it was me, I'd use one until it was gone, then the next and the next.

It's probably OK, I was just never comfortable doing it.

[W.R.Buchanan]

^^^^^^^
What he said ^^^

Randy

[gumbo333]

Use the old one up, if you have a tablespoon or two left dump it in the new bottle and shake it up real good. But that's just what I'd do. Likely never hurt a thing to blend the two, if blended really well.

[rickiesrevenge]

True, unless one lot was bad. Powder gets recalled from time to time.

[BK7saum]

I would use up the old, before the newer powder and not mix the powders.

[gpidaho]

If the powder is only a couple years apart in manufacture date and labeled the same, I use it down to where I'm not comfortable with the powder thrower throwing an accurate charge, then mix the last bit into a new container of the same. I don't think I'd mix in 30 year old powder with new, but then I don't think I ever had powder that lasted me thirty years. Gp

[Larry Gibson]

Mix it and use it, the same powder just different lots. Ammunition factories and arsenals do it all the time. I've been doing it for years. All you're doing is making a new lot of the same powder.

[303Guy]

It's only the age of the first lot that would give me concern. How long will the mix last until used up? On the other hand, I've just bought and found to be fine, a batch of 1967 Greek 303 Brit ammo. That's closer to fifty three years old.

[dale2242]

I`m with Larry.
If all the cans of powder are in good shape, mix well and use it.

[TjB101]

Give that 30 yo powder a good snort and compare to new ... you may end up relegating it to the mulch pile. Did that with some 700x lately. Actually I threw it on a board and lit it on fire ... love watching that trail burn.

[bedbugbilly]

I agree with Larry and I have done just what he says several times - BUT - TjB101 points out what I was going to also say. If what you have is some 30 cars old - check it well to make sure it is still good - and most likely it is if you have been using it without problems. The last thing you'd want to do is mix in a batch of old powder that is or is going bad in with the new and then all of it be contaminated. The "sniff test" should tell you real quick.

[Nobade]

For the competition guns I normally mix large lots of powder. I want to know that the next round is going to do the same thing as the previous round, so having a mixed batch of several hundred pounds of powder is a benefit. If it was just for fun or even hunting where thousands of rounds weren't being fired every year, I don't think I would bother. Just depends on the application, sort of like the commercial ammunition factories. You can bet they don't work up a new load every time they open a bottle of powder.

[mdi]

I've read that powder manufacturers keep under 4% variation of powder performance from the "standard" for a particular powder, lot to lot (I believe the Lee manuals states 3%). I have mixed batches but normally retested the mix for performance and usually seen no difference. But 95% of my reloading is for handguns and I rarely go near max so if there is a difference is is slight and doesn't matter for me/my handloads

[C.F.Plinker]

Email Hodgdon with the lot numbers and go by what they say.

I did this with 4 lot numbers of 231 and they said I could do it if I was certain that they could not have been mislabeled, were stored correctly, etc. etc. I mixed them up with 1/4 cup of each, then added another 1/4 cup of each remixed, and continued until all of the powders were mixed. Then I retested all of my loads and proceeded.

Different story with H110. This time they said not to mix them because I could not be assured of getting the old evenly mixed with the new. Started testing with the new going plus and minus 1 and 2 percent from my old load. There were no pressure signs and the velocities were much lower than the old load using the same j-word bullets and gun. Now I am going to load up at plus 3, 4, 5, 6, and 7 percent from the old load and see what the gun likes. No hurry because I want to test when the temperatures are above 70*.

[JonB_in_Glencoe]

Generally I don't mix powder. But if I am about to load a large batch of ammo, and I know the partial jug of powder I'm going to use will not be enough to complete the batch of ammo I am about to load, before I start, I will blend the remaining powder with a New jug. I don't want to load 1000 rds of ammo, and have half of them charged with one lot, and the other half charged with another lot.

[Cast_outlaw]

The real question is are the few pennies you would save worth the risk of potential catastrophic failures even if extremely remote

[Larry Gibson]

Never considered there to be any chance of a "catastrophic failure" simply mixing different lots of the same powder together. Done too much of such chronographing for 48 year and pressure testing for 14 years of such without any hint of any anomaly to worry about such.

[uscra112]

Mix it and use it, the same powder just different lots. Ammunition factories and arsenals do it all the time. I've been doing it for years. All you're doing is making a new lot of the same powder.

Absolutely. Blending lots is how the factories control the consistency of canister powders. Thorough mixing is key. Factories use drum blenders (like cement mixers). My HS chemistry teacher showed me how to blend liquids by pouring the mix back and forth between containers repeatedly. Might work for powder, too, but watch for static electricity. Metal containers only, and use a static cord between 'em.

[stubshaft]

Been there, done that and have no regrets.