mixing different lots of same powder

[Elpatoloco]

Have been mixing them for 30 years

[mdi]

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.

I believe this is the defining answer. Powder companies' reps will not "go out on a limb" if there is any remote chance of any problem with any product they manufacture. I'll go with real life reports from an unbiased tester...

[onelight]

I am another that has been mixing for years , when my last measure gets down to 1/3 I dump it back in the next can and mix it up , and refill the measure .

[lightman]

I often empty the dregs from one can into a newer can and mix them but I've never blended 30 year old powder with new powder. I might back off from that.

[Shiloh]

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.

I've mixed remnants of one canister with the next one I've opened. The only time I married 2 containers up, was when 2 contaners of the same lot got opened.

Shiloh

[Three44s]

You have two powders that are the same except for their lot numbers, I say if they are close in age, no sweat. But in this example one powder lot predates the other by 30 years.

Because of the age spread I would not mix substantial amounts.

When I get close to the end (not enough of the older powder to substantially fill the measure and trickled) I use the previous Can for my trickler and the newer powder one for the measure.

As the amount in the trickler gets low(older powder) I then dump the two together and mix well.

Three44s

[softpoint]

I've mixed powder of the same type quite a few times. Never had any issues.

[Sam Sackett]

Just curious. I'm not sure if you are loading for extreme accuracy or just plinking loads. If your use is for plinking loads and normal target practice, what would you gain by opening the new container and mixing a big batch? I think I would keep the new container unopened (fresh) and maybe mix the old containers if they have both been opened. If you only have one open, use it to the last dregs as others have mentioned and then mix that with the next container you open. That's what I have been doing for years. Unopened, factory sealed containers are less likely to spoil, get moisture in, etc..

Just my 2 cents..
Sam

[Taterhead]

I normally do dump the dregs of one can into the next.

Exceptions -

The remains are really old.

Powder with the same name, but different manufacturer. E.g. a lot of DuPont IMR 4198 that I recently finished was made in USA. It has a different shape and density to the successor IMR 4198 that is made in Canada. Or the many variations of Accurate No. 9. No. 9 has been made in Belgium, Israel, and the USA. The USA (St. Marks) stuff looks nothing like the stuff made in the Belgian plant. I wouldn't mix those.

[fredj338]

I mix lots all the time, rifle or handgun, doesnt seem to matter.

[mdi]

Just curious. I'm not sure if you are loading for extreme accuracy or just plinking loads. If your use is for plinking loads and normal target practice, what would you gain by opening the new container and mixing a big batch? I think I would keep the new container unopened (fresh) and maybe mix the old containers if they have both been opened. If you only have one open, use it to the last dregs as others have mentioned and then mix that with the next container you open. That's what I have been doing for years. Unopened, factory sealed containers are less likely to spoil, get moisture in, etc..

Just my 2 cents..
Sam

I think the intent of this thread is what to do with a small amount left in the bottle and adding it to a new bottle, not home blending larger amounts. I do. Like if I am loading 80-100 rounds of a cartridge that takes 10 grains of a specific powder but I only have approx. 100 grain left in a bottle and just dumping that into a new bottle...