Mixing Different Lots Same Powder

Discussion in 'Reloading' started by hnts4fun, Aug 12, 2019 at 6:22 PM.

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  1. Zep

    Zep Well-Known Member

    Dec 4, 2011
    I have never mixed powder. My reloading mentor frowned on it. Told me when I get older and my mind is not what it is as a kid it would be easy to screw up.
  2. Lefty7mmstw

    Lefty7mmstw Well-Known Member

    May 13, 2012
    I rarely notice any issues with alliant powders from lot to lot. I've got 5 or 6 different lots of powder in my rl25 jug and she's just fine. That said, I don't try for new frontiers and usually use more cartridge than really needed to attain a velocity.
  3. Heym500

    Heym500 Member

    Sep 22, 2016
    not only do I mix different lot #s I mix same lot #- during pressure testing we saw varying pressure with same lot - mixing fixed it !
    Frog4aday likes this.
  4. crkckr

    crkckr Well-Known Member

    Feb 27, 2014
    I recently compared two different lots of RL7. The newer lot was noticeably slower than the older one. Those I did not mix. There can be be a very real difference in lot numbers.

    However, if I purchased 3 pounds of the same lot of powder, I would not hesitate to use all three with the same charge, even over a long period of time. Store them properly and the chances of one degrading significantly more than the others is very low. I don't think mixing them is necessary.

    If they are of different lot numbers and you have not worked up a load with them, then by all means, mix them together. Make sure your mixing container is large enough to hold all three pounds and pour them all in at the same time. That should be enough mixing but stiring with a paint stick for a few minutes should suffice to mix them completely. Don't get too enthusiastic about it, you don't want to break any of grains down. Return them to the original containers, filling the first 2 as full as possible and tapping the sides to pack the powder in as tightly as possible (getting as much air out as possible), then seal tightly. Be absolutely certain to clearly and permanently mark the containers as 1 thru 3. When these are gone and you need more you will have to work up again.
  5. Impulsive

    Impulsive Member

    Apr 7, 2010
    Different plastic used for the powder thrower.
    All I'm saying is, if you are going to mix powder, try to use the container it came in if you are trying to avoid static.
  6. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004

    When I shot matches that required several hundred rounds a month,
    I bought powder in 8 pound containers and found that over a short period of time the powder degraded from the first moment it was opened to the last loading's because every time I re-opened the bulk container the humidity had an effect. so much so that I stop'ed buying bulk and went back to 1 pound containers. Each 1 pound container would load around 175 loads and that was enough to get me through the month most of the time.

    When I bought 1 pound cans with the same lot # I found no change from one can to the next because when I opened it for the first and last time I loaded all that It would. I use out of one can at a time and leave the others sealed to stay fresh. I have some rifles that take over 120 grains of powder, but I don,t shoot them more that 60 times a month. So I just prefer not to open a powder container more that once or twice in some cases.

    Again, this is just the best way I have found to buy and take care of my powder. If it is the same batch # it should be ok to mix, but many will read this to be ok to mix different lot numbers of the same powders and hear in lies my problem with saying it's ok.

    Keep in mind that Powder is manufactured and sealed with a certain moisture content. Once you open it that can change. (Especially on the gulf coast where humidity is normally between 70% to 98%).

    As to the mixing ease, I have worked in plants that mixed pellets to different percents that would take hours and special machines to get the samples to come out right in each sample even though they were added by %/weight in the beginning as sample were taken small samples had to show the same % to be considered mixed properly.
    Just pouring it back and forth several times realy don't mix it uni-formally.

    Just My Opinion

    Last edited: Aug 15, 2019 at 9:31 PM
    Michael Smith likes this.
  7. jasonco

    jasonco Well-Known Member LRH Team Member

    Feb 11, 2009
    swing away merrill.jpg
  8. MagnumManiac

    MagnumManiac Well-Known Member

    Feb 25, 2008
    I just went through several pages of my previous years notes shooting F-class with 6.5x47, 264WM & 300WM. (Yes, I am old school, I still use belted mags in comp)
    Prior to mixing my powders, H4350, H1000 and RETUMBO would show significant lot to lot variations.
    As much as 100fps in either direction.
    After blending several lots, including 3 8lb kegs of H4350, the largest variation in velocity swings was just 20fps. This is vastly different to the change from one lot to the next. H4350 was by far the worst for lot to lot variation.
    Oh, so was Varget early on in my SR F-class rig in 22-250AI.
    So, if anyone says that blending will cause higher ES, they're talking out their butt.

    As I stated earlier, if you blend PRIOR to working up loads, it it what it Is, you may just find a more stable blend as I have more so than not.

    Frog4aday and jasonco like this.
  9. Coyote_Hunter

    Coyote_Hunter Member

    Jul 24, 2019
    I often mix 1 lb containers when I have multiple new ones. Then I mark each one as part of the same batch. Big container, stirred a long time with my hand and fingers. have been doing this for years with no problem.
  10. nvschütze

    nvschütze Well-Known Member

    Aug 5, 2019
    Your hands and fingers have oil on them. Gunpowder and oil is not a friendly mix...
  11. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004
    Just an adder to my last post on mixing powders.

    I didn't say No one could/should mix powders I only stated my recommendations and experiences with doing it and what I found while doing it.

    I had the mixing thing proved to me back when we loaded duplex loads to get better powder burns. A good friend and an old sage warned me about the dangers and being bullet proof in my younger years I blue him off until he showed me the error of my ways. We were at the range and I was shooting my "Special duplex load" and things were looking good until he took one of my rounds and started shaking it. after a few minutes he handed me the round and said fire this one into that group. although all the powders were mixed in exactly the same percentages and order, some mixing could occur
    and change the burn rate. I though I had that covered by slightly compressing the load to prevent mixing/dilution.

    The round impacted nearly 2" from all of the other hits. he told me that even though I had taken steps to prevent mixing the two powders, that some mixing would still happen and change the performance of the load. I never loaded duplex loads again.

    True, these two powders were different but just like stated before different batches are different even if slightly. So I never recommend mixing different batches for that reason alone, But other reasons mentioned. I just like things to be predictable so I try to un-complicate as many things as possible. Another good post was the increased possibility of making a mistake. If you leave the powder in the original container and don't poor it into something else, and don't have any other powder on your loading table, the odds go way down that a mistake will be made.

    Just my way.

  12. Wedgy

    Wedgy Well-Known Member

    Feb 9, 2013
    That's a really good point. I've never loaded the wrong powder or got them switched around to date but I have learned not to answer calls and get distracted when I'm reloading.
    tmfisher57 and J E Custom like this.
  13. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004
    I almost go in to solitary because distractions can be dangerous.
    I learned years ago not to load while my children were up and I would not be distracted. I started cleaning everything off my loading bench except what I was going to use and it may have saved me when I loaded some ammo and noticed that I had several different powders within reach and when I pulled one bullet I realized I couldn't be sure which powder I had used and had to pull and dump every load to be sure. not knowing which powder I had used also meant that I couldn't pore it back in ether one so I had to dispose of all of It. A small price for a little piece of mind.

    I realize that I am anal about many things, but with over 50 years of re loading I have not encountered anything that good procedures could not overcome, so as things like this happened I simply changed my procedure to safe guard against problems that can be eliminated.
    Unfortunately, the more we do something the more complacent we get. So I try to follow a regimented procedure that becomes routine that has these safeguards built in, like turning my phone off. :):):)

    tmfisher57 likes this.
  14. Greyfox

    Greyfox Well-Known Member

    Jan 21, 2008
    Like most aspects in this sport, opinions and practices vary greatly and are based on the individuals results.... for their particular use. While most see little effect from mixing same lots, aside from the totally incredulous claim or two that, IMO, defy the laws of science, I expect you could practice this for a lifetime and never see any effect on results. This may not be the case with others. I have experienced mixed results. What I find counter-intuitive is that there are shooters that will go to extremes to insist on “same lot” brass, bullets, and primers, but, mix lots of the of the one component, the propellant, which has an order of magnitude in the sophistication and complexity of the production process, and a major influence on results. Whether due to liability reasons, performance reasons, or both, of all the components used to construct a cartridge, it is the “only” one that the manufacturers emphatically state that you should NEVER mix different lots of the same powder....because of “burn rate” variation in the lot specs Burn rate plays a key role in a variety of shooting factors, precision, ES, temperature stability, and pressure with the finished cartridge. Producing the propellant involves the incoming testing of numerous raw materials, processing steps, and test procedures throughout the entire process. Evidently, the current “State of the Art” has not yet reached the desired level of lot to lot consistency.
    While I have certainly mixed my share of same lot powders over the years, since taking up serious LR hunting and competition, I no longer mix. Whether there is a material difference in my results could certainly be debated, I’m more then happy with the results, and the trade-off of not mixing seems irrelevant in the grand scheme of things. IMO.
    tmfisher57, stx and J E Custom like this.