Mixing different lots of the same powder together.

I've been mixing different lots of powders for years I just bought a 8 pounder of IMR 4895 and mixed it with 3 lbs. I had left over, never noticed a difference in performance.
 
Cleftwynd said:
I have always done that, I just mak sure its well mixed. Just recently I mixed a jug of old lot # RL-22 with a new lot, and it works the same as expected.

And although I know it's taboo, I have mixed different powders, intentionally, and developed loads with that as well. I tried this long ago when I discovered some factory that had both ball and extruded powder in the same casing. It didn't kill me or harm my rifle, and I ended up with an excellent load!
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"Blending"" powders is what brought superformance to shelves isn't it?

I'm newest of the new to reloading, and hope I run into this kind of dilemma someday. I keep reading about fresh lots getting topped off with old stock, but OP seems to have a few different lot#'s in small amounts...that'll affect the overall ratios a little differently I'm sure. If OP's load has been the same with the powder in question throughout as opposed to having wildly different numbers (if each lot was worked up differently) should be a consideration.

What is (are) the powder (s) in question, and planned use once mixed?( other than shelf-space)
 
Lots of good advice here folks and thanks for the feedback. The powders I would be mixing are RL-22, 19 and a couple of imr's. I only have 1 lb containers and all but one is simply adding 1/3 to a 1/2 a pound to a new container.
 
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if the 1lbs containers are all one lot number I don't mix. if I had a couple of different lots I tend to mix them together then develop a load. never had an issue and have been doing it for years.
 
Ganderite said:
I do this all the time. I take various jugs and drums of powder (typically 4895) and mix them all together in a clean garbage can, so I get 40 pounds of homogeneous powder of one (new) lot number, instead of 4 or five small and different lots.

There can be a substantial variation between a new jug of powder and old powder. I have a couple of drums of military surplus 4895 that is about 2 grains slower (in 308) than new powder.

I develop a load for a particular application, and having done so, it is nice to have plenty of that powder , so I don't have to do the development with another lot #.
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I've done it as well, not with 40lb batches, but with all that I have so as to have a consistent lot throughout.

Heck, I've even mixed 760 and 414.
 
It is a inventory control thing. First in ....first out. I use up old powder. When switching to different lots, i simply check for POI change. Then i am not ever a load to beyond max person, simply find the accuracy node, so not worried about pressure differences. I am also a hunter, so while very anal and picky in my loading; i am not nearly worried about .2 difference in POI or groups.
 
mossyhorns said:
Folks, although I've been reloading for over 20 years I've never actually done this. While organizing my powders last night I discovered several partial containers of the same powders but in different lot numbers. As powder containers are mostly air anyway I would sure save a lot of space by combining them.

Is there that much difference between lot numbers? Has anyone done this?
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Consider this: from one lot of powder to another, the product (a specific powder model) has to be within a certain quality control range in all respects. Composition, density, granule size and shape, color, taste (j/k!), etc. For our purposes, call it a fictionnal "0.8 to 1.2 range, with average 1.0". All those leftover containers are of the same model of powder, yes? So they are in that 0.8 to 1.2 range to start with. If you mix them together, the result will still be within that 0.8 to 1.2 range and meet the quality control specs for that powder model.

Two caveats to this:

1. Very old or denatured powder: don't use that. Burn it away, because after some years the powder could well have drifted out of that quality control range.

2. Don't mix different powder models, of course... unless you're truly a fearless experimenter and are willing to risk your firearm's and your own health.
 
Yes I've done it, and it makes sense to do. Make sure it's thoroughly mixed, and you'll have to re-do your loads. If you stick with multiple containers of different lots, you'll have to re-do your loads multiple times, so why not just do it once?
 
I do the mixing thing to. When I buy new powder I take it and mix it in with the same powder I already have on hand. I use a large pail with a tight lid on it and pour the new powder in with the older stuff and shake the heck out of it...then stir it up good and then shake the crap out of it again then put it all back in their original containers....I hardly ever notice any deviation in my reloads doing it this way like I used to get when I reloaded using one pound at a time one lot at a time. I guess we all have our own beliefs in how to do things but I have convinced my self with the results I get this is safe to do.

Jim
 
Seems reasonable

Grawfr said:
Consider this: from one lot of powder to another, the product (a specific powder model) has to be within a certain quality control range in all respects. Composition, density, granule size and shape, color, taste (j/k!), etc. For our purposes, call it a fictionnal "0.8 to 1.2 range, with average 1.0". All those leftover containers are of the same model of powder, yes? So they are in that 0.8 to 1.2 range to start with. If you mix them together, the result will still be within that 0.8 to 1.2 range and meet the quality control specs for that powder model.

Two caveats to this:

1. Very old or denatured powder: don't use that. Burn it away, because after some years the powder could well have drifted out of that quality control range.

2. Don't mix different powder models, of course... unless you're truly a fearless experimenter and are willing to risk your firearm's and your own health.
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Ganderite said:
I do this all the time. I take various jugs and drums of powder (typically 4895) and mix them all together in a clean garbage can, so I get 40 pounds of homogeneous powder of one (new) lot number, instead of 4 or five small and different lots.

There can be a substantial variation between a new jug of powder and old powder. I have a couple of drums of military surplus 4895 that is about 2 grains slower (in 308) than new powder.

I develop a load for a particular application, and having done so, it is nice to have plenty of that powder , so I don't have to do the development with another lot #.
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This.

We aren't looking at rocket science here.

There is one caveat however and that is with surplus canister powders. Even though they have the same nomenclature they can be radically different. Especially if they have been developed for one particular load for a specific purpose or the graphite coatings are not what they should be. Doesn't mean anything is wrong with this powder but it does need to be approached carefully.

Mixing off the shelf commercial powders specifically produced for hand loaders is a completely different ball game. They sometimes differ from lot to lot enough so there can be a big difference between the burn rate. Let me give you and example. H414 and W760 data is interchangeable. That doesn't mean they will give identical velocities but my rifles don't notice the difference. I have mixed W760 and H414 together to get a useable lot on more than one occasion and would end up with 8-10 pounds of a mix that behaved very well. Then there was a surplus powder offered by Tom Higginson who used to own AmmoMart before he passed away, called H414SL10. Wonderful ball powder that is slightly slower than H414 and W760. I am using up the last of it this year. Fantastic powder. Temperature doesn't effect it as much as it does H414 and W760. The load ratios are very close in the cartridges I load for so I took a seven pound box of H414SL10 and mixed it with an eight pound bottle of W760 that was a mixture of a bunch of half bottles that came from the estate of a fellow I trusted completely with his loading practices. Nothing at all happened other than I had 15 pounds of and excellent powder that seems to be much more tolerant to cold weather. This winter is so mild it may just be my imagination but my Chrony tells me the velocities with my favorite loads are much closer together between shots and the accuracy hasn't fallen off.

Another couple of mixes I did during the last powder shortage was to mix IMR7828SSC with regular IMR7828 and 4831 from sixty year old lots with modern New Manufactured H4831 both SSC and regular. Both work very well and allow me to use the old powder and still get more into the cases without pressure issues. I use magnum primers for all of my rifle reloads. This may or may not help but if you use your head you can utilize a lot of what would normally be throw away powders.

I wouldn't mix H4831 with IMR4831 but I really don't think there is enough difference between the two to get excited. If I were to do so and I might if I come across two bunches that aren't useable for my purposes to make one decent batch, I would start with the lowest starting load for the fastest of the two and work up from there.

Now, you need to ask yourself what is a useable lot of powder. I know a lot of people that won't use a one pound can of powder over five years. For me that might make a good day of shooting in some cases.

Do not mix powders that you are unsure of. I have two different lots of H1000. One came in some boxes from Higginsons and the other comes from a keg. The lot from Higginsons is much faster than the commercial container I have. Much to fast to mix with the other lot and so fast that it is dangerous to use with any H1000 loads listed in any books or online.

There is a caveat on Reloaders.com that show where other hand loaders have had issues with this same bulk powder. It was made for a government supplier of ammunition for a specified purpose and given a handy designation with likely pertinent information. This was the powder left over and picked up by AmmoMart and others as surplus and resold according to its designation on the barrels it was shipped in.

Ganderite can explain how that works much better than I can.

The big thing is, if you aren't comfortable mixing powders of the same description, even from the same maker, don't do it.

I am not sure how this works but I am assuming that commercial cartridge manufacturers and those that contract to governments will purchase their powder from whomever will supply it the cheapest. If they can save a tenth of a grain or even a grain of powder per cartridge over millions of rounds that can save them a lot of money and increase their profit line exponentially. They will put out a contract for such powder in a certain range to several different manufacturers here in North America and offshore. It's just good business to do so. When they don't use all of the powder or for some reason it doesn't do what is expected of it and if it is a viable powder it goes onto the surplus market or gets sold to another cartridge manufacturer.
 
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