Here is the question:

What is the consensus about combining say three different lots of the same powder into one?

So far I have found results that very from DON'T, to you may experience problems with consistancy.

What are your thoughts?

Not recommended...

ricciardelli,

Answers like yours is what makes me curious. All manufactures claim to have consistancy in the manufacture of their powders, yet I continue to hear answers like yours. Is the consistancy between lots not up to spec as they claim? It will be interesting to see what Hodgdon has to say in their response if they get back to me.

[ 08-26-2003, 02:52: Message edited by: Byron ]

If you get the blend perfect, I can't see what the problem could be.

Unfortunately, one lot pretty much looks like the next, so how would you know you got a good blend?

Most factory lots are actually blends, and even the commercial packers get into trouble sometimes, like Alliant did with the RL22 lot a few years (?) back. Some cans were way faster than others.

That said, I've done it, so do what I say, not what I do..... lol! Dutch.

Dry mixes of different powders (not just rifle powder, but any powder) tend to separate. If you're mixing vitamins, and put 100 pounds of one item in, followed by 200 pounds of another, and 150 pounds of another, the mix will get more random with time, then less random, and back and forth in a fairly predictable way. This is because the different components have very different densities and particle sizes.

However, most batches of the same powder are so similar in density and granule size that I doubt this would ever be a problem.

Statistically, if you mix one-pound jars of powder, the resulting batches will be much more uniform in characteristics than unmixed batches.

I say there is very little potential downside, and good reason to believe that mixing of powders that are the same maker and number, but different lot numbers will produce greater uniformity.

Preferably, load some identical rounds with each powder lot, and shoot them (ideally over a chronograph). If they are close to the same in pressure indications, velocity, etc, go ahead & mix them. You then have one "new" lot of powder that will last three times as long as the three individual lots, and that you can develop loads with one time & not worry about having to work on three different loads, wasting time, components , and barrel life each time.

Yeah, I know... we live in a litiginous society & I'm being reckless. So here's your standard disclaimer... Do this at your own risk. If somebody isn't comfortable with this, then simply don't do it.

I've done it for years with no problems. I habitually take the last quarter of a can of powder and put it in with a new can and then roll the can to blend the powder and continue loading. The results have been amazingly uniform. I have read all the post about every time you change the least component, you should start all over again. Perhaps you should; I don't. I think reloaders of today are very lucky, indeed blest, with the uniformity and QA of the products we use.
I understand that bench rest shooters, when they find a powder, bullet, etc that works well for them, buy as much of the same lot as they can afford. I think to find the difference between two ordinary cans of say 4350 with different lot numbers one would have to be a much better shot than me.
I will include the same disclaimer as Cold Bore: Kids, don't try this at home. This post is for balance of perspective only. (whatever that means)

beemanbeme...

If you mix last year's honey with this year's honey, will the blend be the same as last year's or this year's?

To the guy who just wants to pour some honey on his waffles, he probably won't notice the difference. But to the honey expert, he will know the difference...the true expert will even be able to tell the difference behind hives, pollen, and bees...

Beemanbeme--I do the same as you and have never ever had a problem or seen a difference. I usually let the can get down to a little less than 1/4 full before the transfer. AND I always make sure the powder is of good quality.

Now I'll really get in trouble with the guru's. I've even taken a clean tumbler bowl and taken 2 half full bottles of powder and added them slowly together and tumbled for about a minute. (not longer to keep the coating on the grains). Then put them back into a single bottle. I always felt the less air in the bottle the less it will deteriorate.

OK--now I suppose it will be time for me to get blasted but I've never had a problem doing that either.

This may be a stupid question, but where is the lot # printed on the powder container?

Different manufacturers do it differently, but it's a good bet you'll find it either stamped on the bottom of the container if it's a steel can or on a sticker if it's a plastic bottle. You'll know you've found it because it will not look like anything you recognize; they do it that way on purpose.

[ 08-27-2003, 05:56: Message edited by: rootbeer ]

Trying one more time....

Mental experiment: Start with 25 1 pound jars of the same powder, different lots. Pick any 5, and thoroughly mix them. Repeat until you have made 5 5-pound mixtures. Now, test each one of these 5 pound mixtures for muzzle velocity, using some given load.

Without boring you with gory math, the resulting muzzle velocity variation will practically always be much less (i.e., better) than 5 random jars of powder from different lots, pulled at random off the shelf.

Mixing powder practically always improves uniformity.

Buy mil surplus powder in 8# jugs, or get a whole case of them with the same lot number, then shoot for a long time on the same stuff.
As long as your not loading on the ragged edge of pressure extremes, then I wouldn't see a problem with it as long as you dropped down a bit and tested after mixing.

Byron

Here another approach about consistancy and mix powder.
First of all, I have not experience of reloading lots of ammo with different production batches of USA powders to aswer your question for yes or no.

In my case,I reload with locally manufactured powder for Practical Shooting (IPSC).
First, I need to maintain velocity between the minimum required by the IPSC rules and a maximun, as low as possible, to get minimum recoil.
Second,smoke must be as less as possible to let see multiple targets in rapid fire.

To have no surprises , I buy several cans of the same production batch . Before buying, I ask professional reloaders if the batch I am going to buy produces an acceptable smoke level.

Then, I mix all in a bucket, the rest of the powder I have been using with all the powder I buy.
Afterward I put all the mixed `powder into their original cans.

This is only applicable for the powder I will reload for competitions.

By this way, I am sure that both , velocity and smoke, will be under control during for a long period of time.

I hope it could be usefull for those cases of consistancy doubts.
Best regards

BA Shooter

Well you guys are coming up with some interesting and good points of view. I wish I knew what Hodgdon's was but they have yet to respone to my question so I sent them a second request.

Thanks for your input, none of it is being ignored.

I think the only way mixing 2 lots of the same powder could ever be a problem is if one is radically different from the other and your mix wasn't thorough. Loads from the top of the can would be different than loads from the bottom.
I too mix the last bit of one can in with a new can.

Hello, my name is Ed, and I've mixed lots of the same powder type for years. {sob . .}

I try to buy 8# cans of anything I use a lot of. When I get low, I buy a new 8# can. I thoroughly mix the remainder of the first can with the new powder. I then start off with the new batch as if it were a totally new lot of powder, which it actually is. I start with a slightly reduced load until I can see the characteristics are similar to the last lot.

I've done this with Red Dot, Blue Dot, H-380, IMR4895 and H-870.

I would NEVER blend types to achieve a modified burning rate.

I would NOT treat the combination of lot numbers as having any similarity to either original lot number without testing the new batch, though I've never seen a substantial difference.

Eshell, oh no, I'm not talking about any sort of duplex load nor mixing powders with different burn rates. I'm talking about mixing two cans of 4350 or going from one cannister of 4350 to another without a new work up.

Imagine working up a load for a .416 Rigby, and then you realize that you will only get 70 rounds from that can of powder.

Would you work up a new load again after every 70 rounds?



I mix.

Rick.

In working up a load for my Lazzeroni 9.53 Hellcat I used RL 15 and the 300gr Nosler Partition.....in the 1st lot of powder I got to 2450 fps using a specific weight of powder and had to stop because of definite pressure signs.

I switched to a different lot of the same powder and worked up to the same weight of RL 15 as before and the load that gave 2450 fps and definite pressure now gave 2550 fps and no signs of pressure. Would want to blend these two lots of RL 15 and if so, for what purpose?

The thing that is most likely different about the two lots is the quickness. If you mix them, you will most likely get a quickness that is between the individual quicknesses. Whether this serves any purpose is something you would have to determine for yourself.

There is every reason to believe that mixing improves uniformity.

Something can be uniform, but not desireable. Brahma bulls are very even tempered--always mean and ornery.

O.K. guys I got a response from Hodgdon on my second request for information and here was their answer. But before we go there here is the text of the message I sent so everyone is on the same page.

"As I stated in my original e-mail I have three different lots of Varget.

1 0017003670
1 0219963144
1 1105013381

What I am trying to determine is how to decypher the lot numbers to know which is the oldest to use it first.

My second question was the companies opinion/concern about combining powder of the same model, Varget in this case, but different lots to produce a larger consistant lot instead of 3 smaller lots with possible variance from lot to lot."

Their response was:

"You have lots for 99, 01 and 03. Yes, you could blend them to get one homogeneous lot.

Mike Daly
Customer Satisfaction"

Now I know that sometimes people get in hurries and other times they don't comprehend totally what was being said, or written in this case. I now know that I have powder that has 2 years seperation between being produced but not which lot is which year and no explaination on how to determine it from the lot numbers. So, I have no way of knowing which lot to burn up first. The only logical assumption that I could make is that the numbers were progressive so the lower number is the oldest and so forth, but there is no guarantee. So that leaves me with my second option and that is to combine the 3 lots and produce a single lot.

Reports I have heard on another site was that newer lots of Varget had lower velocities then the older lots produced. Based on this information and the fact I don't use max. loads I shouldn't encounter any problems if I take care to ensure a good mix of the lots. Although I like the idea of using a vibrating tumbler to assist in the mixing process I know mine is not anti-static so I will stick to stainless steel bowls. I think I will do it like this: Divide each lot into three equal portions and then combine one portion from each lot and mix well so I have three equal size combined lots. Then combine the three batches mixing as they are poured into the larger bowl and mix a little more. This will probably provide me with the most uniform mixture. Since the physical makeup of the lots are identical, as they can be, there should not be a problem with any sort of separation.

My rough calculations indicate I should be able to load about 950 rounds of .308, after an initial verification on the desired load, and with any luck consistancy should be about as good as starting with an 8 lb keg.

As I said earlier I appreciate all your feedback so, Thanks Again! If anyone has anything else to add please do as I will monitor this topic till it dies a natural death. Darn, I think I only have a 500 count box of Sierra 175 gr Match so guess it is off to the Reloading Center for more bullets. Do you think I ought to worry about them being a different lot? JUST KIDDING GUYS, DON'T FLAME ME

[ 08-28-2003, 05:19: Message edited by: Byron ]

edited to kill double post . . .

[ 08-29-2003, 20:30: Message edited by: eshell ]

Im not afraid to mix lots of powder, I just don't. I'll trickle the last load out and any remainder fertilizes the yard. Definately an arguement for buying in quantity.

In retrospect, one must appreciate the wonderful consistency of IMR and VihtaVuori powders. I know I do. A few years back I ran into pressure problems with H1000 and RL22, both were much faster than I thought they should have been. Probably an arguement for blending, but I chose to use something different.

Hodgdon has since moved on to the "extreme" line and I know the "reloader" series is quality stuff and I still use their products, but I still prefer to use other powders.

O.K., I mixed the 3 lots and loaded up the first 150 rounds and headed to the range. What followes is what I posted on another site. For reference my rifle, referred to as "SCLE", is a .308 with 24" Mike Rock 5R 1-11.25" twist with Palma Match chamber.

Range Results,

Well I went out for Desert Marksman's 1000 yd practice day Sunday and that's what it turned out to be. The individual who normally runs it had to work and those that showed didn't have a big interest in shooting paper so it was only metal clanging. 20" and 36" diameter plates at about 1060 yd. Still hadn't had a chance to chrono the 44 gr Varget load so just dialed the -06 dial on the M3 to 1000 and fired for affect. This range has to be the hardest to read. Elevation is about 4320, shooting up a valley from a small outlook with at least three different side valleys cutting into this one from the side and the backstop is the end of a canyon so the winds tend to swirl. By the time I got dialed in I was at 34 MOA with 2 MOA right on last contact with 20" steel. Well everyone else decided to call it quits by 1200 hrs so I headed for the benches to chrono the load.

Temperature stabilized at 91 degrees in the shade so I was glad I brought my MULE. I only had 22 rounds through the tube so decided to chrono with fouled bore. Loads were once fired Federal match prep'd cases (normal uniform primer pocket, debur flash hole, necks turned to .014", FL sized with Redding .355" neck bushing, weighted 170 + or - gr), Sierra 175 MK seated to 2.200" (Stoney Point - .004" off lands), Federal GM210M primer, and 44 gr Varget (Pact Digital Dispensor and Digital Scale used to trickle last couple tenths of powder). Speaking of the powder it was a mix of 3 different lots (1999, 2001 & 2003) of which I had 6 - 1 lb canisters. I didn't what to worry about velocity differences and having to check each lot before starting to use it. Checked with Hodgdon and they indicated no problem. I asked about how to break down the lot number so I would be able to tell on future purchases and was told the first number is the package size, next 6 numbers are the canning date and the rest is the lot number. Now the lots I had were, 1 0117003670, 1 0219963114, & 1 1105013881 so can you tell me what sort of calendar they are using cause I sure can't figure it out. Also, BP was at 29.55 with winds running 0 - 8 MPH. Almost forgot, chrono was Pact Professional set 15' from muzzle of my SCLE so without any further delay:

HIGH: 2723.9 FPS
LOW: 2708.2 FPS

SD: 4.6
CV: 0.17%

MAD: 3.5
CV: 0.13%

AV: 2713.7 FPS
ES: 15.7 FPS

For comparison here is what Federal Match 175's chrono's at on the 17th at elevation of about 700' or so at 88 degrees unk BP:

HIGH: 2769.1 FPS
LOW: 2719.2 FPS

SD: 15.1
CV: 0.55%

MAD: 12.1
CV: 0.44%

AV: 2748.1 FPS
ES: 49.9 FPS

I think I did good in the reloading department ;-) Trouble is I over shot the 2685 FPS I was aiming for or was the temp and elev that stepped up the velocity? Question: Does altitude affect the chrono results since you're only dealing with 15' from muzzle to screens? Well, after 3 days at the range today will be celebrated with pondering results and cleaning gear.

Later,

(End of copied post)

Well if this first batch is indicative of the rest I will sure hate to run out of it