Joe,

  Doesn't sound like a good idea. I just use the current lot till it gets so low I can't use it any more and then throw the little bit left out in the yard.

  The makers suggest you don't mix lots together. Smokeless powder that's sold to the public has each lot blended to work within certain pressure limits for given grain wgts, so you can expect the different lots you buy will work pretty close to the load you've found best for a particular gun. Mixing lots might possibly change these limits for the worse giving pressure spikes that might cause some problems.

  Also never break down factory ammo to determine what powder they are using and the wgt. Powder sold to the ammo makers is not blended and is sold to them with proviso they will test each lot on their own and adjust their loads accordingly.

PETE