Mixing Different Lots Same Powder

[dolomite_supafly]

I used to but I don't anymore.

The reason why is even though the powders are the same the individual grains can vary greatly. And lots with bigger grains will float to the top and smaller grains work their way down.

Here is a powder reference with microscopic pictures. You can see different lots are different sizes and often use different ingredients. The different ingredients are probably used to standardize the burn rate.
http://www.ilrc.ucf.edu/powders/search.php

 

[J E Custom]

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.

Very well said !!! Now that is a real word smith.

Some say that they cant tell/see any difference in accuracy or results in many of the things we talk about. And it is very hard sometimes to measure these results. Many times it is only thousandths of an inch improvements that results from the change. To some, that is not enough to take the time to do something if it doesn't net a 1/4 MOA change.

I have personally gone from being happy with a 1 MOA accuracy standard to sub 1/10th MOA. Of coarse you don't always reach these goals, but some of us try. (Its our thing).

It is relatively easy to reach 1 MOA with good equipment. It is much harder to reach 1/2 MOA and requires great detail in all of the things we discuss. If you are looking for 1/4 MOA it is another world and you can leave no stone un turned.

Beyond 1/4 MOA is where the little changes of .020 thousandths more or less start to add up, and the term Anal comes into play. Buy being open to change and testing the change I have improved consistent accuracy from 1/10th MOA to less. Is it worth the effort ? to me it is the satisfaction that I learned something and improved a .091 5 shot group to .073 and in one case the average group size of .072 went to
.054. That is only around a .020 thousandths improvement but it is also almost a 30% improvement.

So as in many things we talk/discuss on this site. the elimination of any variable can improve consistency in performance to some degree.
The man that started me down the road of being finicky would go to a bench rest match and use one case for the whole match. when ask why, he said whats more consistent that One case. He never mixed powder, and used out of one container, he measured every bullet diameter, he weighed every bullet, measured the meplat and tested 5 or more cases to find the one that gave him the best group and that is the case he would use in the match. To his way of thinking, everything could be improved if he could just figure out what change to make.

Most of us are not bench rest shooters, But long range requires the same Dedication to accuracy and details, and in some instances different philosophies and equipment for the extreme range.

J E CUSTOM

 

[Chuckrub]

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2175-91462015000400398

 

[MagnumManiac]

While I tend to try my own experiments, there comes a time when what was tried and recommended decades ago no longer translates to today.
The coatings and additives used today in the process of nearly ALL double base powders makes them practically water resistant.
Having a pressure trace, and physically seeing the difference between lots, especially in the early days of Barger, as you US guys no it as, here where it is manufactured, it is known as AR2208.
anyway

 

[J E Custom]

I was just looking at different powders and in the process I found this warning from Hodgdon powders.

https://www.hodgdon.com/warning/

Please read and decide for your self.

I realize that everyone in the manufacturing of components tries to eliminate liabilities. But if it were not a problem they wouldn't bring it up.

There are so many reasons NOT to mix powders and only one real reasons to mix powders "COST".

If I am down to just a few ounces of powder left in a can, rather than mix it with another can of the same lot. I just let it feed the lawn and start with the new sealed can/container.

J E CUSTOM

 

[Wraith Hunter]

Very well said !!! Now that is a real word smith.

Some say that they cant tell/see any difference in accuracy or results in many of the things we talk about. And it is very hard sometimes to measure these results. Many times it is only thousandths of an inch improvements that results from the change. To some, that is not enough to take the time to do something if it doesn't net a 1/4 MOA change.

I have personally gone from being happy with a 1 MOA accuracy standard to sub 1/10th MOA. Of coarse you don't always reach these goals, but some of us try. (Its our thing).

It is relatively easy to reach 1 MOA with good equipment. It is much harder to reach 1/2 MOA and requires great detail in all of the things we discuss. If you are looking for 1/4 MOA it is another world and you can leave no stone un turned.

Beyond 1/4 MOA is where the little changes of .020 thousandths more or less start to add up, and the term Anal comes into play. Buy being open to change and testing the change I have improved consistent accuracy from 1/10th MOA to less. Is it worth the effort ? to me it is the satisfaction that I learned something and improved a .091 5 shot group to .073 and in one case the average group size of .072 went to
.054. That is only around a .020 thousandths improvement but it is also almost a 30% improvement.

So as in many things we talk/discuss on this site. the elimination of any variable can improve consistency in performance to some degree.
The man that started me down the road of being finicky would go to a bench rest match and use one case for the whole match. when ask why, he said whats more consistent that One case. He never mixed powder, and used out of one container, he measured every bullet diameter, he weighed every bullet, measured the meplat and tested 5 or more cases to find the one that gave him the best group and that is the case he would use in the match. To his way of thinking, everything could be improved if he could just figure out what change to make.

Most of us are not bench rest shooters, But long range requires the same Dedication to accuracy and details, and in some instances different philosophies and equipment for the extreme range.

J E CUSTOM

J E, you are correct. Very few shooters have the knowledge, persistence, patience or dedication to become extremely accurate. The original question about mixing lots of powders is a good example of someone who is seeking the information to become an excellent shooter. I applaud the question!

For myself, I am almost 70 and I find I am able to accept less than incredible accuracy for simplicity. I use slow burning powders, Reloader 22 or MRP exclusively for all of my Weatherby reloads. My load workup is such that, with a larger magnum case, I use a conservative load. Sure, I give up a few FPS, however the conservative load allows me to mix lots of the same powder, forego: measuring powder humidity, only reload when the powder is at the same temperature as the workup load, measure individual case capacities, measure each bullet for weight, measure bullet diameter and length of each bullet etc. I am careful with case length, neck length, free bore and I use a trickle charger for each cartridge. Yes, I have and do mix lots. In the end, I am comfortable shooting game out to 600 yards. I have never needed more than one shot to harvest an Elk, Deer or Bear.

I realize mixing different lots of fast burning powders is probably not a good idea, especially when reloading in a case with less capacity that a magnum.

 

[J E Custom]

J E, you are correct. Very few shooters have the knowledge, persistence, patience or dedication to become extremely accurate. The original question about mixing lots of powders is a good example of someone who is seeking the information to become an excellent shooter. I applaud the question!

For myself, I am almost 70 and I find I am able to accept less than incredible accuracy for simplicity. I use slow burning powders, Reloader 22 or MRP exclusively for all of my Weatherby reloads. My load workup is such that, with a larger magnum case, I use a conservative load. Sure, I give up a few FPS, however the conservative load allows me to mix lots of the same powder, forego: measuring powder humidity, only reload when the powder is at the same temperature as the workup load, measure individual case capacities, measure each bullet for weight, measure bullet diameter and length of each bullet etc. I am careful with case length, neck length, free bore and I use a trickle charger for each cartridge. Yes, I have and do mix lots. In the end, I am comfortable shooting game out to 600 yards. I have never needed more than one shot to harvest an Elk, Deer or Bear.

I realize mixing different lots of fast burning powders is probably not a good idea, especially when reloading in a case with less capacity that a magnum.

I totally agree with you and your reasoning !!!
If a person knows the cause and effects of any procedure, with experience he can make a decision that works for him and be happy with the results.
My concern is the inexperienced re loaders developing bad habits that could get them in trouble or hinder/slow their normal progression to better ammo and accuracy. there is always the safety issue that should be of concern for those that don't understand what traps they can set for themselves.

I am soon to be 78 and have learned most of these lessons the hard way and only want to help others avoid the same mistakes if I can.

As an experienced shooter and re loader Like you I understand what happens if I do certain things and can work within there safety range, But I would never tell someone with limited experience to do the same. (Do as I say, Not as I do)

As my shooting skills digress, I rely on Subtle things that can make up for my shortcomings. So one or two SD improvement and/or .010 thousandths improvement in group size is worth the effort to me If only to add confidence to my performance. I always want the rifle to out shoot me.

Just Me

J E CUSTOM

 

[jbs2014]

Three years later we are now in the midst of a powder shortage the likes I've never seen before. The days of being able to go out and buy 5 8 lbs jugs of Retumbo are in the past.

Did anybody try mixing different lots after this thread was finished? If so what were your results?

 

[Reelamin]

I pour two at a equal rate using a funnel into a empty can. Grab the third do the same. Then split and repeat several times mixing them together. load it, shoot it and don't think about it again. Still works just fine after 45 years.

 

[TR1Hemi]

I dont match shoot, so..........lately I HAVE been blending new 1# into existing 8# jugs. I mean it is not like you are mixing brands of 4350, or ball with extruded, or different speeds, only the exact same powder. I have only done this with H335 for 5.56 and 6.8 loads, and Universal for 9, 40, and 45. If you cant trust lots to be "essentially" the same, then can you really trust that brand? If mixing a new lot with your old lot causes pressure signs or loose primer pockets, then you were probably living near the edge, and that new lot unblended probably would have blown the gun up. Again, handgun and plinking ammo only, not match ammo. The trick is pour some in, shake, pour some in shake...and shake before use. Over the long haul your powder is more probably consistent, the transition from lot to lot is far less noticeable, if at all.

 

[tvarden]

What??? So my 2lbs Hodgson CLAYS with 2lbs Hodgson H1000 and a 1/4tsp of H110 with a dash of US869 did not make Varget??? Well back to the drawing board!!

 

[Deputy819]

Did anybody try mixing different lots after this thread was finished? If so what were your results?

I just did this a couple days ago, actually. Had 12 lbs (total) of 3 different lot #'s of IMR 4198. Ordered a 1.6 gallon HDPE container from US Plastics and put it all in there. Added 1 lbs of each lot # at a time to make 3 lbs and then rolled the container around on the floor for a few minutes to mix ….did this 4 times. I haven't shot any of it yet as I'm still waiting on my SML build to be completed, but I'm good on powder for a while.

1.6 Gallon White UN Rated HDPE Wide Mouth Drum with Red Lid - Stackable | U.S. Plastic Corp.

These plastic drums with screw lid closures are perfect for pharmaceuticals, specialty chemicals and food ingredients. The drum protects ...

www.usplastic.com

 

[jimbires]

yes , this works just fine . all you're doing is making your own lot of powder . what @Deputy819 explains above would be about the best way to get a good mix . I've kept a couple empty 8 pound powder jugs to do my mixing in . the 8 pound jugs of alliant RL33 , RL50 are big .

 

[Ol' Red]

What??? So my 2lbs Hodgson CLAYS with 2lbs Hodgson H1000 and a 1/4tsp of H110 with a dash of US869 did not make Varget??? Well back to the drawing board!!

You forgot the 2 ounces of Tannerite