Blending Powders

[ILVTOHT]

I'm not one to want to blend powders but a question about blending the same powder, let's say Varget with different lot numbers.
If I blended different 1 lb cans into 8lbs of Varget with three different lot numbers and then did my load work ups. Would there be a reason this would not work?

I've been doing this since the 80's, I buy a 5# or 8# keg and when it gets down a couple pounds I pour in a pound or 2. Shake it up and go back to reloading.

I've found if you do this you never have to rework a load. I never run a keg empty!

 

[rcar112]

That's what I keep hoping for !!

 

[entoptics]

I work with very precise instruments, measuring the chemistry of rocks. We have to take a fist sized rock, turn it into powder, then take an aliquot and mix it with a flux, eventually taking about an 1/8 teaspoon of powder for the final measurement.

Mixing is our 2nd largest source of error (#1 is getting a homogeneous aliquot). An ex-student of mine now works for a paper coating company. His entire job is streamlining and improving their mixing processes.

That said, I mix powder all the time, exactly as you mention, but I mix it VERY thoroughly. As in several minutes of turning, tumbling, shaking, rolling, etc. Be gentle enough not to pulverize anything, but be thorough. Tip end to end 20 times, then roll it over side to side 20 times, repeat.

 

[villagelightsmith]

I do mix everything on occasion for entirely different reasons. (A friend used to do that, and called it his "Monkey Powder." He actually shot the stuff.) I just leave it around until I need to do a demonstration of how powder burns ... Pour out a little trail of the stuff, stand back and toss a match at it. Kids are always fascinated ... mothers are always horrified ... Dads often go fascinated with the kids unless the mothers are around. As for dads who are horrified, show them the door. They are sorry, useless drones, "educated" to the point of pussification. Sometimes you can get them to examine their "feeeelings," both before the show and in retrospect after the show, and maybe very gently (poor fragile souls!) teach them [help them learn] "something," perhaps even of value. Like, distinguishing "Apparent hazard V.S. Real hazard," and "Who do you trust?" Neighborhood teaching opportunity.

 

[Swinehunt74]

Recently purchased a couple of 1lbs of Re-22 at gun show {supposedly new]. Topped off 5lb jug I had. No, I didnt check seals, and one had pistol powder mixed in. Thank God it wasnt much [dont need a bunch for rifle]. Loaded my 338 Lapua with 300 gr pills and had REAL STICKY BOLT. NOt to mention vel of 2875. Stopped right with 338. Grabbed my 300wm and sent first round down range and Yep, I realized i had used same jug last week as 338. Great velocities with 210's around 3100 and

 

[Swinehunt74]

Stiff bolt. Upon examining when home and starting knocking out ALL loaded bullets with that mix, i discovered the pistol flakes in whole batch. Now that part of yard has some very expensive fertilizer.....Lesson, dont buy non new powder and mix with known New stuff. Grateful I wasnt hurt and lesson learned...First and last time i mixed powders. Reloading over 45yrs too.

 

[rcar112]

Glad you didn't get hurt and secondly damage your rifles. Thanks for the added info about what and where powders are from and what might have out of your control.

 

[Ingwe]

In the past we had to use duplex or even triplex loads. we had to keep them separate and had to compress the powder charges to keep them in their proper place without mixing. some of us tried mixing Different powders and even the same lot numbered powders the results were all over the place. The conclusion we came to was that the blending process was not sufficient to get a perfect blend unless it was done for a long time.

So the best results were to first try to buy powder with the same batch numbers, and use each canister totally up if you had a good load. then when you went to the next canister start with a 1 grain less load if you were at max and adjust the weight by small increases until you have the same results. (Normally there will be a very small shift in POI and/or velocity) even with the same lot numbered powder. If you cant buy matching lot numbered powders, then it is recommended that you start testing the load when you start using out of the new canister.

If you mix/blend powders you will most likely see different SD,s and velocities even an occasional flier.

Many people blend or mix powders but if you are a accuracy nut you will find that the end results
are never as good when you mix powders.

As stated in the past, 1 MOA is easy, 1/2 MOA is hard, 1/4 moa Is very hard and accuracy in the .100's will have extreme consistency with no stone unturned, and nothing overlooked.

J E CUSTOM

JE, when using a new canister of the same powder but from a different lot number, how much velocity change is there usually?
What is the biggest difference you've seen?
I'm using VV N565

Thanks!

 

[nksmfamjp]

It would be very interesting to me how powder makers and comercial reloaders handle these issues. I'll bet they don't have much waste.

it would be interesting what lot to lot variation looks like at a powder maker.....or even what a "new lot" means to them.

 

[243winxb]

In the manufacturing process, smokeless powders are recycled and reworked (National Research Council 1998). When a powder within a batch is found to be unsatisfactory, it is removed and returned to the process for use in another lot. Manufacturers save money by recycling returns by distributors or the return of surplus or obsolete military powders. Hence, reworking and recycling the material assures good quality control of the final product, reduces costs by reusing materials, and reduces pollution by avoiding destruction by burning.

http://www.firearmsid.com/Feature Articles/McCord_gunpowder/

 

[243winxb]

CONCLUSION The great advantage of the spherical powder manufacture process is the possibility of using deteriorated and unstable nitrocellulose. Aged powders that would be destroyed can be reused, which results in a lower production cost.

https://www.researchgate.net/publication/285583098_Characteristics_and_Manufacture_of_Spherical_Smokeless_Powders

 

[epoletna]

My understanding of the blending process by manufacturers is that they burn a specific (small) amount in a closed container called a bomb, I think. They are able to measure the burning speed and the specific energy. Then by mixing one lot with another they can pretty closely duplicate what the previous lot did.