I remember reading somewhere that it's ok to mix different lots of the same powder in order to get greater consistency between your loads. Being that it's hard to find 8lbs jugs Varget I feel that this would be conducive to my needs right now. I'd hate to have to keep reevaluating my load formulas every time I burn through a 1lbs bottle, and it would save me a great deal of space with all of these 1lbs bottles I've been hoarding.......and does anyone have spare empty 8lbs jugs laying around?

I have done that with IMR 4895.  I accumulated 5 pounds that all had different lot numbers so I mixed em up in an empty 8 lb bottle and made a few test loads.  I had nothing bad happen to me!  With pistol ammo and plinking ammo I doubt I would mix them.  I have never noticed much more than 20 or so fps in variation from lot to lot but I am kinda particular about my M1A loads.

Ken

I have never read that either, at least not in any formal publication anyway..  I have however read  that you should not do it from powder manufacturers.  Now, if you go read on any of the benchrest or hardcore reloading sites you will find people that do it all the time.  I guess the reasoning is that you now dont know the true lot number in case of a recal?  I dont know?  I do know that when you go for super consistent accuracy that even a small difference from lot number to lot number can cause undesirable changes in pressure and velocity, especially if you load to the max.  Thats exactly why I try to buy in 8lb containers or at least 1lb containers with the same lot number. 

Ken

There's no way a powder manufacturer will ever state in writing that it's ok to mix them and I'm guessing that may be purely based on a legal stand point to protect themselves. I remember reading about it on another forum in a reloading section and I specificly remember that the main question was what large container could be used to store the new mixture. I'm pretty sure an empty 1gal bleach container was used in the end due to it being non-transparent and a certain HDPE number classification. I've Googled it a couple different ways and besides the recall factor I have yet to find a logical reason not to do it. And this is of course being done with "new", off the shelf powder. I wouldn't do it with a new bottle and an old bottle of granddads powder. 

I've mixed different lots of W231 with no ill effects, though 90% of my loads are well below max.