Powder consistancy questions

[demented]

 I have two one pound cans of IMR 4064.  One can is over five years old, the other just bought a couple weeks ago. What I am asking in my usual long winded way is if loads worked up with either of these will be safe when using the other can?  If safe, will POA vs POI be close enough for that occasional 300 yard shot? Caliber is 308 Winchester, with 150 gr. PSP bullets. 

[Graybeard]

I've not personally noticed that much difference but if you're worried about it just pour both into a larger container and mix them thoroughly and then put them back into their cans and what you'll have is a consistent powder in both cans. I've done this in the past and no doubt will again in the future.

[Lloyd Smale]

Like Bill said usually theres not much differnce but some lots can vary and the only way youll ever really know is to try it on paper.

[Questor]

I never load to maximum, so I feel safe in not re-testing when getting a new can of powder from a different lot.

[PA-Joe]

If you use powder bushings to drop your charge you should weigh them and not rely on the tables. I have noticed a 2-3 bushing change between powder batches and the tables!

[Catfish]

Canister powder is very consistent from lot to lot and I never worry about it. If you are talking about surplus lots of powder they are a totally different matter, and you need to start over and work up a load with each new lot. I shoot alot of surplus powders and like to buy in 50# at a time so I don`t have to work up loads all the time.