Mixing lot numbers

[Rodney]

I’m about to finish an 8lb jug of ar-comp. Bought six one pound containers from Gander mountain when they were closing. 3 have the same lot# and the other 3 have the same lot#. My question is it bad practice to mix the lots together in the empty 8 lb jug or should I just keep the two lots separate and use them accordingly.

 

[22DASHER]

Mix them and then work up to your load just like normal.

 

[LHSmith]

I would keep them separate. How would you mix them to guarantee the results would be one homogenous powder? You could affect the burn rate if mixed too aggressively by breaking down the deterrent coating.
Why not chrono the two at the same charge and see if there is any difference?

 

[avidflyer]

I always just mix.

 

[ImBIllT]

Mix. They are already very close. If one shot has 53% A and 47% B and the next shot has 49% A and 51% B that might be a problem if you blended two different powders, bit it won't be a problem blending lots. If you always blend, then you will very rarely have to tweak your load. If you never blend, then you will often have to tweak your load from lot to lot.

 

[bloc]

Mix. Unless you are a precision competition shooter, in which case any variation might screw your score.

I do not believe that slightly different burn rates of two different lots will be significantly different from either of the two lots, when the two (or more) are mixed. But you could easily test that.

And the protective coating will, IMO, not be affected. When I think about how brutally powder is treated during military operations in distant lands, with wild temperature changes and jiggling in places like Afghanistan, and when I consider that most of the powder we use has been shipped great distances, with temperature and vibratory extremes, from manufacturers within CONUS and from some more distant manufacturer (one in Australia or Europe), it seems unlikely that degradation of a powder's coating would be at all significant.

I am open to the possibility that actual data falsifies my conclusions.

 

[Rodney]

Thanks for the advice. I’m relatively new to reloading, and this site is a wealth of knowledge. This powder is for my factory guns , so a little variation would not be critical.

 

[dkhunt14]

Thanks for the advice. I’m relatively new to reloading, and this site is a wealth of knowledge. This powder is for my factory guns , so a little variation would not be critical.

With your factory guns, it probably wouldn't show. I have seen lots that just would not shoot at 1000 yards. Big variances in velocity, by over 10 percent. Even when adjusted they didn't shoot as good. Matt

 

[powderbrake]

I would not mix them. I would use one lot number, see how it shoots, rezero the rifle if necessary. When that lot is gone, do the same for the next lot.
I am not saying it is bad to mix the lots, I'm just saying that no specific good comes from the mixing. Keep the containers sealed until you need to open them.

I have had instances when knowing the lot number of the powder was helpful (a friends rifle blew up), and I had some bad primers which flame cut my bolt, knowing the lot number helped to resolve the compensation from the powder and primer vendors.

I now label all my rifle reloads with the lot numbers of the powder, primer, bullet , and case(when available). I do not mix reloads with any changes of lot numbers, they go into their own box.

 

[MGYSGT]

All you do by mixing them is to create your own lot number. Big deal.

 

[dkhunt14]

All you do by mixing them is to create your own lot number. Big deal.

Years ago there was a lot of Re22 that was extremely hot. It was over 5 grains hotter. I called them and they replaced it. Even offered to pay for damages caused. If you mixed that with another, you probably just messed it all up. There is no way of mixing it thorough enough. If you had a hot and a cold lot, there would be hot and cold spots throughout the mix. Matt

 

[1lnbrdg]

I work in a plant that manufactures extrudates (not gunpowder).

Several extensive tests have been run on how to best blend different lots of the same material. Put all into a single container, pour thru a funnel 3 times into another container. About as good as it gets.