Thoughts on mixing powder lots?

[gohring3006]

So how would combining and blending be worse than multiple 1lb containers of powder with differing burn rates? This doesn't strike me as rocket science - my thorough and careful blending of separate lots of 1lb containers into one single, uniform lot of powder. How much worse could it be than fighting 3 separate burn rates. Unless, of course, you don't believe uniform blending is possible. If I can assemble better cartridges than factory ammo, I have confidence I can adequately blend some powder.

I blend differing lots of powder without concern. Wouldn't blend 20-year old powder with new powder, but when I burn 100gr of powder per shell fired, I can't see continually fighting differing burn rates every time I open a new 1lb container from a different lot.

And their are times when 8lb containers cannot be had.

There are exceptions to all manufacturer's recommendations, as many times recommendations are established to increase profits, more than any other purpose. If one doesn't understand the basis for a code or recommended practice, then by all means follow the code or recommended practice.

I used to do the same thing you describe. But now I put to much work into all the case prep, to just blend some powder and wonder why my ES varies from load session to load session. With that said, I never really had any accurcy problems by blending different lot# 1pound containers... I personally choose not to. I have seen different lots of powders take me right out of my node when I switched.

Don't even get me started mixing different lot #s of primers.. Nope!!!

 

[SansSouci]

All you have to do, is run different lots over a Chrony and it will tell you the lots are different.

No. It would tell you that something is different, not necessarily powder. You'd have to assure all variables are consistent except for powder lots. That's be nearly impossible to do.

 

[SansSouci]

This reminds me of an engineer I used to work with. Both of us liked theory. The difference is when we went to the shop and implemented out theory and it didn't work, he could not adjust and make corrections. Poor guy was consumed by the idea the theory should work.

Theory without facts is fantasy.

Facts without theory is chaos.

 

[J E Custom]

So how would combining and blending be worse than multiple 1lb containers of powder with differing burn rates? This doesn't strike me as rocket science - my thorough and careful blending of separate lots of 1lb containers into one single, uniform lot of powder. How much worse could it be than fighting 3 separate burn rates from 3 separate containers. Unless, of course, you don't believe uniform blending is possible. If I can assemble better cartridges than factory ammo, I have confidence I can adequately blend some powder.

I blend differing lots of powder without concern. Wouldn't blend 20-year old powder with new powder, but when I burn 100gr of powder per shell fired, I can't see continually fighting differing burn rates every time I open a new 1lb container from a different lot.

And their are times when 8lb containers cannot be had.

There are exceptions to all manufacturer's recommendations, as many times recommendations are established to increase profits, more than any other purpose. If one doesn't understand the basis for a code or recommended practice, then by all means follow the code or recommended practice.

In a perfect world, Blending would be ok but this is not a perfect world and different lots/batches of powder are sometimes not the same so the problem is getting a perfect mixture of different powders without damaging the powder. There was a post a long time ago about tumbling loaded rounds to clean up the brass. that also had a downside and that was because It damaged the coating and altered the burn rate. (Coatings are to aid in consistent burn rates and minimize heat sensitivity). so damage to this coating can/will change the burn characteristics.

When I switch to a new lot/batch of powder I test over a chronograph against the older lot so I know exactly what the change if any is in both SDs and velocity And can adjust if I have to. (Some times I see no difference, but some times I do). with blended powders I found an occasional flier with different velocity and SDs than the rest and had no real explanation for what happened. now when I do get a flier it is much closer to the same velocity and the SD change is very slight. So by not blending I have eliminated one more possibility and look at my loading process to see if I may not have done as good as I can.
I use to be thrilled with SDs in the teens, now I consistently get below 10 ft/sec and most of the time if I do my part, below 5 ft/sec. I would like to reach zero but I am not sure that is possible with so many variables in re loading, But I try.

For me, this has been the best way to manage the difference with large quantity powder charges.
my 50 bmg took 250+ grains and a 1# can didn't last long but I had no problems with adjusting to new lots of powder (Normally less that 5 rounds of the new, and 3 rounds of the old).

Hey its ok if anyone wants to blend there powders, I just choose not to because of the reasons posted.

J E CUSTOM

 

[gohring3006]

No. It would tell you that something is different, not necessarily powder. You'd have to assure all variables are consistent except for powder lots. That's be nearly impossible to do.

It's very easy, if I have a lot of powder giving me 2700 fps average and a ES of 5 with a SD of 2.5. Then I switch only the lot of powder and those numbers change. Well... The powder is the difference.

 

[Outlaw6.0]

I blend, out of necessity as others have said previously. Whether be it luck or other mystical inclination, I'm still alive and my rigs are still in one piece.

Knowing that lot inconsistencies are commonplace; I ensure that my new "lot" of mixed powder is treated just as starting a brand new load work up. Start low and go from there. It works... If a person doesn't feel cool with it, that's fine; don't.

Much like personal preference to bullets, stocks, optics and so forth I believe that mixing your own "lot" of powder falls to individual choice and propensity.

Is the new "lot" as consistent as an individual lot from the manufacturer? Hell if I know, but my bullet still hits the target so.... I guess it's good enough for me.



t

 

[Pdvdh]

When I finish blending powders, they look the same as they did when they weren't blended. I don't see a pile of dust in the bottom of the empty containers. I just end up with 3lbs of powder that's more consistent than the differences between the three different 1lb lots of powder. If I see a difference over my chronographs or on the target I can pin to blended powders, I'll reconsider. I shoot a lot of my bullets over a triplicate chronograph that provides 4 separate velocities for each bullet fired. I don't see any greater variance with my blended powder than I do between the three individual powder lots.

I'll straighten out a bent nail and re-use it to fasten two pieces of lumber together too. My guess is the manufacturer of the nail would advise I purchase another box of their nails. I'm employed in a field of work where some practitioners can't get enough perfection. It verges on witchcraft and voodoo, what I observe from some individuals in practice. They can never attain good enough. They keep seeking the pot of gold at the end of the rainbow their entire careers, never accomplishing arrival where the rainbow touches down on planet earth, and spending excessive time and money in the process.

Trust me when I state I'm tainted with a touch of obsessive/compulsive disorder. How many shooters do you know that have constructed a chronograph setup that provides 4 separate velocities for each bullet fired, and each chronograph records a velocity within ~4fps of the average individual bullet velocity 99% of the time?

After I conclude I can blend different lots of powder without ill affect, by the time I'm done blending my separate lots of powder, I sleep like a healthy baby. Folks that can't sleep at night because they've blended different lots of powder? Yeah, you'd be nuts to blend differing lots of powder.

 

[Buttermilk]

The Superformance powder offered by Hornady is a blended powder. If you open a can of theat and look carefully at it you will see differing powder kernels.

Hodgdon's even told me so on the phone some time back it was a blend.

Hornady also has about 14 different blends of this "same" powder used in factory ammo. But only one canister version released for the reloader.

Personally, I blend different lots of the same powder and don't have an issue with it.

 

[Kansaswoodguy]

I've discussed this concept with other loaders. Some swear that powder varies from lot-to-lot. If powder does vary, then it is not copy of the original. It would be a new powder.

Gunpowder is chemistry. As long as identical chemicals are used in precise proportions, lots should be identical.

I'm not in the industry so take this for what it's worth. Any variance in the manufacture of the raw materials that may very well come from different places from lot to lot will be reflected in the final product making getting exactly the same burn rate from lot to lot quiete an art. I think the manufactures work very hard to get it as close as they can from lot to lot but there are differences as many have experienced threw out the years. Does anybody have a link to where a manufacturer suggests not mixing lots? I've never read this anywhere not that I'd stop mixing them but I am curious. I've never seen any evidence of a down side in the way of powder degradation from my mixing of lots but I'm not using my wife's kitchen mixer or my brass tumbler either.

 

[JGalle]

I had some variation in 1 pound cans of H4831 chronographs. Enough to make separate ballistics charts for each can. I then bought an 8 pound keg. More variation. So I bought several more 1 pounders and blended about 12 pounds now labled Batch 1. All chronographs the same now. Makes too much good sense. Now I blend specific powders that I have several cans of. Keeps the paper work down and saves the barrels.

 

[Oldschool280]

blended them and now im good for a while, thanx guys

 

[Pdvdh]

I blend specific powders that I have several cans of. Keeps the paper work down and saves the barrels.

Yup. Me too.