Changing Powder Lot #

Reloading
1

A rather newbie reloading question but what the heck.

I will probably go ahead and create my 2024 hunting ammo soon. Pre-hunting season it’s 90° with 90% humidity here. Right now it’s much drier and cooler.

I will probably load up 20, but may go ahead and do 50. However, I only think I have enough powder in my current container for probably 10. I have another container of the same powder, but it’s a different lot number.

Do I need to redo pressure testing with the new lot number?

Is it a bad idea to have 10 rounds in a box with one lot of powder, and another 10 or more with another?

Thanks

2

95% of the time, I see no change when switching lot numbers.

As long as you’re not pushing max pressure, I wouldn’t bother to redo pressure testing. I’d just shoot the 20 and check on a chronograph to see if there’s a significant change in velocity.

If there is, I’d first point to a change in how the containers are stored given the high humidity. It’s always possible there’s a real difference between lots. I’ve seen it, but it’s rare.