Mixing powder...

[skeetman28]

Has anyone found a quarter lb. of powder and another container of the same powder but differant LOT #'s and just combine them together and then load with them combined ? Is it safe as long as you don' t go to max on the load...

 

[biggen]

Yes, I'll mix lots #s as long as I'm not using it for one of my bench rifles. I wouldn't suggest doing it if you loading right near the "ragged" edge on pressure.

 

[ScouT6a]

If it is the same brand of powder and type (number), I would probably mix them.
Heck, my Speer reloading manual doesn't even want you to mix different types of cases. Some of that is just CYA on their part.

 

[indyjohn]

I'm sure it is done often. Many (most?) will wave you off of this practice (mostly to protect those who, as biggen points out, are loading at max pressures).

I want to believe that with the level of industrial technology we enjoy today, mixing lot #s is not as risky as it used to be.

But I've been known to be wrong before...

 

[Broom_jm]

Going strictly "by the book", no...it's not safe. The powder in each one of the two canisters you started with was blended at the factory to achieve certain properties. This makes the burn characteristics predictable, such that load data for that powder is safe and reliable. When you "blend" two different lots of powder, you really have no idea what end you are achieving.

If this is for mid-range plinking ammo, where you are a well below MAX, you can get away with it. If it's for high-quality accuracy loads, you've just (metaphorically) shot yourself in the foot. What if you mix those two powders together and start shooting the best groups of your life?

The right thing to do is use up one canister with a known load and the drop back a grain or two with the new lot of powder, quickly working back up to the accuracy and/or velocity of the previous load. You have to watch for signs of excess pressure along the way. That's the only truly safe way to go about it.

 

[warthog]

I will blend two different lots of the SAME powder but never two different powders. As stated, not for my bench rifles though.