mixing powder old with new

[Scibaer]

i have a bit of IMR 3031 left over,  say enough for 10 rounds or so. i went out and bought another can of 3031 ( great stuff  by the way ) ..
so, can i pour the left overs into the new can ? safely and use it all the same ?
or is there something i need to know ?

[wncchester]

" can i pour the left overs into the new can ? safely and use it all the same ?"

Yes.  It's nice to shake the can a bit to mix it well, but there is no reason at all not to do so.

[revbc]

Scibaer,

I'm not an expert reloader for sure, but I know powders can vary some lot to lot.  Some more than others.  I have no experience with the powder in question, but to be on the safe side, why not load up the 10 rds and be finished with that lot?  Just my opinion.

Bobby

[BBF]

NO  NO   NO 

[moosie]

Load the old powder separately and do not mix with the new.  Although no break down is evident, if any degree of it is present, it might have a catalyic effect on the new powder.  Better to use up the old next time you reload.
Moosie

[AtlLaw]

I guess this is one of those subjects that has been discussed in every reloading group that exists.  Some say yes, some say no.  After years of consideration let me give you my views.     BTW, the sound you hear out there is the gnashing of teeth and beating of breasts by other members because you have given me an opportunity to pontificate!     Therefore, as unaccustomed to public speaking as I am   , here goes.

If you want to mix em, go ahead.  but remember:

As handloaders we strive for consistency.  Heck, we worry about the flame length and burn duration of the primers we use!  Now, everyone knows (at least we have been told by people who should know) that the characteristics of powder may vary from lot to lot.  So, if you mix 2 cans of powder, if they are from the same lot, you should be okay.  If they are from different lots you may be okay, but you also may have altered the burning characteristics of the whole can; assuming even distribution of a significant amount of diverse powder that is.

Look at it like this, which is better, good single barrel sippin likker or single malt scotch, or some cheap butt blended whiskey, or, in Alabama, shine run through one radiator versus two... 

Anyway, when you mix significant amounts of powders from different lots you can assume that:
you have altered the characteristics of the resulting powder; and
the data you have carefully worked up over the useful life of the former lot must now be, at the very least, verified.

But!  Logic tells you that the amount of the resultant alteration of the characteristics of the new lot of powder is dependant on the amount of dilution by the old lot of powder.  So!  Any resultant alteration by the introduction of, say 10 rounds worth of powder should be minimal to non-existant!  Right?     Right!    ... well, maybe...    Who knows?  Because:

We unfortunately have no idea what the characteristics of the new lot of powder are as it is... well, a new and different lot!  So we got to reshoot and verify our data from the old lot, then mix in the old powder with the new powder and reshoot the data and compare the old lot, new lot and mixed lot do determine if there is any significant alteration.     Of course by this time we have shot up most of the new lot which is actually the mixed lot including the old lot and have to buy a new, new lot and mix it with what is now the old/new/mixed lot and...    and... well, you get the idea.   

Now I know that, bein frugal and all, it goes against people's grain to not get full use out of what they have.  You see, I mix together the last little bits of soap bars to get a new big bar, put some water in the bottle to get the last drop of ketchup to come out, that kind of thing.     So I once mixed together 2 cans of 4895 together.  I used it all up, but I was never comfortable with that can of powder.  When it was gone I vowed never to mix powders again!  Especially one marked IMR with one Marked H...    Gimme a break y'all!  they both said 4895!   

Anyway, nowadays and just to satisfy my anal personality, durn!  there's somethin awful soundin about that!     Nevertheless, nowadays if I can't load one more round from a can I just through the last bit of powder on my lawn or stick a match to it and clap gleefully when it goes Pffffffit! 

[wncchester]

Well, we can safely assume that any two lots of otherwise identical powders ARE virtually the same, otherwise it would be a different powder.   Anyone who actually mixes perhaps 300 gr. of old 3013 with 7000 gr. of new 3031 really isn't going to see any changes at all.   We aren't talking about mixing 3011 and 4350 here so the differences, while real, is going to be a tiny change in already tiny differences in the lots to be very  useful anyway.  And no safty conderns of pressure is possible at all. 

Since Mr. Scibaer is asking this question, it seems safe to presume he is a NEW loader.  The probiblity he has been using a 30+ year old can of 3031 is remote.  Therefore, the fear of mixing new powder with some aged powder that may be faulty seems almost searching for a justification for an irrational fear.

Every one chooses what he's afraid of.  We can be ruled by a childish fears of "dark places" or we can be grown-ups.  The more we understand what's going on in reloading the better the light is, and we can better focus on areas of real danger, of which there are plenty but it's not in mixing a few bits of (very effectively) identical powders. 

(In some 45+ years of freely doing so, I've only blown up maybe 6 rifles.   NOT!  )

[the jigger]

I've been handloading for over 30yrs and have never mixed powders of different lots. I don't know why, I just don't do it! Maybe in my early days one of my mentors said " Don't do it!"
GOOD LUCK and GOOD SHOOTING!!!

[AtlLaw]

Looking over this I realise my ending made it seem I was taking a stand for not mixing old and new powders.  Heaven forbid that I ever give a yes or no answer!     So allow me to add another - short - paragraph to my previous post.   

"... nowadays if I can't load one more round from a can I just through the last bit of powder on my lawn or stick a match to it and clap gleefully when it goes Pffffffit!"

I could just as well add that last bit to a new can if I were so inclined.  Right now I've got an old can of RL15 with a new can sitting next to it.  Every time I look at them I try to tell myself to mix them together.  I just can't do it...  not yet...   I will however, load up some more rounds for my Whelen with powder from the old can then, when the amount left reaches some mystical mark that my mind says is to small an amount to make any difference, I may pour the remainder into the new can.

So gentle OP, consider what has been said here, come to a conclusion that is reasonable to you and you are comfortable with and procede in that direction without fear.    

[BBF]

Reason for my triple NO's is that once you start this sort of thing it will probably get to be a routine.

The small spoonful this time may lead to two spoonfuls next time and then the following time might be a bit more and so on.

Load up the old stuff with however many you can get, the rest gets lit up outside. When you are done with the batch of old loads start fresh and verify your zero.

[Graybeard]

I ALWAYS do it personally. Maybe if you're one of those who has taken 30 years to use up that can and will take another 30 to use up the new one you shouldn't but me I'll continue to do it EVERY TIME.

[mechanic]

I just went to my Brother's and picked through my Dad's old reloading stuff.  It has not been touched since 1989 when Dad died.  There were about 20+ cans of powder.  I have used some of it already, along with the primers, and have had no problems.  Its hard for me to believe that there is that much inconsistency between lots of the same kind of powder to make a significant difference......but then I don't claim to know much.

To get to your question, personally, it would'nt bother me a bit to mix it.

[krod47nw]

Load the old powder separately and do not mix with the new.  Although no break down is evident, if any degree of it is present, it might have a catalyic effect on the new powder.  Better to use up the old next time you reload.
Moosie

I would be more worried about this, than differences in lots. 
Kevin

[mechanic]

"... nowadays if I can't load one more round from a can I just through the last bit of powder on my lawn or stick a match to it and clap gleefully when it goes Pffffffit!"


Makes dang good, if expensive fertilizer........grass will green up nicely.

[Mule]

I have mixed powders, of the same designation and manufacturer, with different lot numbers.   
It has always been rifle powder.
I weigh every charge.  The data doesn't change as long as you are not playing with ancient propellants.
I would not mix pistol powder that runs through a powder measure.  It is not unusual to see small changes from lot to lot.   A responsible reloader should recalibrate his powder measure when opening a new can of powder.  If the "mix" is not mixed thouroughly, how can you have trust that the measure is throwing a safe charge?
I am reluctant to mix shotgun powders also, because they are dispensed by volume and a change in bulk will change the actual thrown charge weight.  Promo is blended to burn like Red Dot and uses Red Dot load data.  But Promo is not Red Dot.  Promo is an economical target powder, but it is not consistent batch to batch.  My charge bar must be recalibrated every time I open a new jug of Promo.

My advice.  For the beginner, don't mix powders.  After you have gained some experience and understand the ramifications, mix at your own risk.

[LaOtto222]

I am with Bill on this. When I get a small amount left in one jug, I pour it over into the next jug and mix thoroughly (same powder, same brand). I just treat it as a new lot of powder. I work up a new load each time I do this, you are supposed to work up a new load with a new lot number anyway - you do that right? Rarely have I had to change powder charges, however. I usually drop .5 - 3  grains (depending on case capacity) from my normal powder charge and if that is OK, I work my way back up to my original powder weight. I do not waste a bunch of powder, I load up 3 and chronograph them (I used "signs"; before the chronograph). If I get predicted results, I increase powder weight until I get back to my original FPS load. Only one time over the years have I had to change my over all powder weight. It was in a 22 Hornet, using W296. I ended up using .2 grain less for one lot of powder, that I mixed. The next batch was mixed into another lot and I was back to my original powder weight. Like I said, the new lot of powder is unknown any way, so if I mix in a different lot of powder, it is still unknown - what is the difference? Good Luck and most certainly Good Shooting to all.

[Lloyd Smale]

ive dont it for over 30 years and never had problems because of it. Just shake it well and treat it like a new can of powder knowing the burning rate can change from lot to lot and you will have no problem.

[Savage]

How many times have we refilled a powder measure with powder from a newly opened can? Speaking for myself, thousands of times. If a powder varies enough from lot to lot as to be dangerous in the same loading, the manufacturers would not be in business long!
Savage

[Badnews Bob]

I've done it. But if its one pound cans they never last long enuff around here to get old. I have just started to buy eight pounders of my favorite mix so that may change.

[LONGTOM]

While some may do it and others may not I never have.
The only thing keeping me from doing it is that last little bit in the can is mostly in crushed powder form, or dust.
There is always dust at the bottom of a can of powder.
If you keep it mixed each and every time there may not be very much but there is always some.
For that little bit of powder I woun't take the chance.
Just my thoughts!
Haven't blown one up yet and don't want to!!!


LONGTOM

[Scibaer]

wow, thanks for the thoughtful replies. yes, i am a new reloader, but active and spend alot of time reading, testing my loads and spend alot of time in my gun room. i dont have cans of powder that are old, they may be a few months old at best. i tested and loaded up enough rounds for my contender in 30-30 to use up a full can of IMR 3031, and have a bit left over. that can is 1 month old. so, now i go and buy a bag of new brass and another can of 3031. yes, i still work up the load with new can ( new brass, same primers  and new bullets ) so it gets treated like im working up the load from the beginning, but this time i have a "target" load ( what worked for the other 100 rounds was 28 grains of the 3031 )
so, relying on the fine folks that work at IMR powder co. i can ( cant i ? ) trust that the new 3031 will be the same, for all practical reasons as the older can of the 3031 ( time can sat on shelf at store is unknown ) i should just pour the cans together , mix well and work up my load...

now if i have 7000 grains per can, and i use 28 grains per load. 10 rounds would be 280 grains. that 280 grains mixed into 7000 grains of a full can equals .04 ( four hundredths ) of 1%  0.04% is was to small for me to worry about.

so, after reading all the comments i will mix the same type of powders if the amount is small, and the powders are not to old, if i have question of that i dump it.

[AtlLaw]

I just treat it as a new lot of powder. I work up a new load each time I do this, you are supposed to work up a new load with a new lot number anyway - you do that right? Rarely have I had to change powder charges, however. I usually drop .5 - 3  grains (depending on case capacity) from my normal powder charge and if that is OK, I work my way back up to my original powder weight.

+1

[Varmint Hunter]

I've been reloading for 30 years. I have periodically dumped small amounts of powder into a fresh can of identical powder. I shoot almost all of my reloads over the chronograph and have never seen anything that would suggest that this practice is a problem.

I do NOT mix old powder with new powder. If powder has been laying around for years, even in a cool, dry environment, I chuck it out. Actually, I put it my wife's flower garden. 

[Scibaer]

agreed. i used the term 'old' a bit sloppily. i understand that some reloaders have 'old' can of powder that are 10 or 15 years old or more sitting on their bench. my cans of powder are not nearly that old.

just as a thought, im now going to use  a sharpie marker and put a date on all my containers, that way i know when i got them.

[cwlongshot]

Personally, I don't ever do it.

If your loading on a single stage press, you can get right to the last little bit of powder with out a problem. So whats the issue? With this stuff, I ALWAYS air to the side of safety.

 Now having said that, I do conseed that the likely hood of it causing a problem, as long as the amount is tiny, is small.

CW

[carbineman]

wow, thanks for the thoughtful replies. yes, i am a new reloader, but active and spend alot of time reading, testing my loads and spend alot of time in my gun room. i dont have cans of powder that are old, they may be a few months old at best. i tested and loaded up enough rounds for my contender in 30-30 to use up a full can of IMR 3031, and have a bit left over. that can is 1 month old. so, now i go and buy a bag of new brass and another can of 3031. yes, i still work up the load with new can ( new brass, same primers  and new bullets ) so it gets treated like im working up the load from the beginning, but this time i have a "target" load ( what worked for the other 100 rounds was 28 grains of the 3031 )
so, relying on the fine folks that work at IMR powder co. i can ( cant i ? ) trust that the new 3031 will be the same, for all practical reasons as the older can of the 3031 ( time can sat on shelf at store is unknown ) i should just pour the cans together , mix well and work up my load...

now if i have 7000 grains per can, and i use 28 grains per load. 10 rounds would be 280 grains. that 280 grains mixed into 7000 grains of a full can equals .04 ( four hundredths ) of 1%  0.04% is was to small for me to worry about.

so, after reading all the comments i will mix the same type of powders if the amount is small, and the powders are not to old, if i have question of that i dump it.

Personally I think you might run into a problem with the "new bag" of brass weighing in at slightly different weights, and goofing up your loading than you would with the propellant. I've had 30-30 brass weigh in at around 130 grains and others weigh as much as 143  grains after being sized and trimmed. Now if the outside is sized the same then the inside diameter is different or the web is thicker on one. This type of stuff never ends when reloading mettalic cartridges.

I just ran thru an 8 lb container of BLC-2 and could only find three 1 lb containers to replace it locally. I dumped all three into the 8 lb.container and will test it over the chronograph. If you can afford it, in the future I would buy the biggest container within reason, of your favorites and go from there. That way you have one less thing to think about. After more years of reloading than I care to admit, while I still use good work habits and double check all phases, I tend to not sweat the minor details as much as in the past. I'm not telling you to work unsafely, just to verify when mixing and matching, and you'll be alright.

Some years back I read a webpost on another forum about a bullet manufacturer that endlessly tested various primers for brisance or power, When the tests ended, they were set to publish the results, and decided another batch of primers should be tested first. The second test showed differences in the primers and the rankings changed dramatically. The strongest large rifle primer tested the 2nd go around was the CCI 200 which was one of the more milder in the first round. The bullet company scraped the report, after that I was convinced that just when you think you know something for sure, it all changes. Good Luck and Good Shooting

[SingleShotShorty]

Never mix two powders of a given type unless they are the same lot numbers. Powder lots can vary quite a lot at times.