Changes in powder formulas?

[Socalman]

I was given some powders by a friend whose father was a serious reloader. I can tell by the meticulos notes I found.

My question: Do the companies ever make minor changes to the formula for a particular powder? Some of the dates on the sealed cans go back to 1985! However the opened ones seem to be ok. Can I just follow the load recipes in my manuals as if the powder is new or is there a chance the powder recipe has changed slightly over the years, in which case I should start by working up from a minimal load?

[Divernhunter]

Yes they have.
You can still use the load data from the newer manuals. OR you can use the data from the older manuals.
I would just use what you have unless you are at or above max load. Then drop back a bit(no need to go to min) and work back up.
Some of the changes the manufactures have made deal mostly with ease of production, source of production(country for example) and making the powder less dirty burning. Burn rate are something they try not to mess with. If it will be a lot different then they just call it a new powder name.

Enjoy your free powder...……...or you can send it to me for proper disposal

[MongooseV8]

Lots of changes over the years but most are minor. Make sure to use published data and start with minimum loads.

[JagerDog]

Mostly what he said. An exception is I'd refer to newer data. Ex: old data could call out 125gr loads in .357 Mag with Blue Dot. That combination has been nixed by the mfg in later data. Some current "max" loadings are lower than old "max". Some is due to better instrumentation and I'm convinced some is lawyers. Generally I try to confirm 1 source with another...or two.

[bruce381]

As I understand the cannister powder what we buy is a blend sometimes of the comercial or not available to us powders to get the "namned" powder into range or adjusted to the set spec the powder has.

Say they have a batch of W231 that is too slow or fast, it is blended with a slower or faster version to get it on spec.

Then is sold to us reloaders, I think commercial powders DO vary from batch to batch and they have to be calibrated as lot#'s change or that's what I think anyway could be wrong.

[mjmagee67]

N320 changed a few years ago...I had to add .2 to .3 gr to get the same velocity as I did prior. My original load was well established and well chrono'ed. I was checking velocity for a USPSA match and noticed it was a tad slow. I checked Brian Enos and several others were seeing the same thing.

[smoothy8500]

Over the 20 years of reloading various powders, Accurate Arms 2520 powder has seen the biggest swings in the recipe related to pressure and velocity. Most powders I may test and change a half grain at most (many don't need any change). However, AA powders get a full start-over because it seems every lot acts like it is a completely new formula.

[popeye4]

Over the 20 years of reloading various powders, Accurate Arms 2520 powder has seen the biggest swings in the recipe related to pressure and velocity. Most powders I may test and change a half grain at most (many don't need any change). However, AA powders get a full start-over because it seems every lot acts like it is a completely new formula.

That characteristic alone would make me avoid AA powders. There are too many good ones that don't do that.

[smoothy8500]

That characteristic alone would make me avoid AA powders. There are too many good ones that don't do that.

I agree. When this last lot of 24lbs is done, I'm done with it....

[sl0re10]

That characteristic alone would make me avoid AA powders. There are too many good ones that don't do that.

+1... if there are changes... change the name of the powder.

[Socalman]

Thank you all for your answers. They confirm what I believed to be the case. I can use my newer load manuals (2103 and up) with the older powders, just not at the max level.

[divingin]

As I understand the cannister powder what we buy is a blend sometimes of the comercial or not available to us powders to get the "namned" powder into range or adjusted to the set spec the powder has.

Say they have a batch of W231 that is too slow or fast, it is blended with a slower or faster version to get it on spec.

More than just that. A too-fast powder often will have powdered graphite or other coating added to retard ignition, thus making the powder "slower". (Varget seems to show this pretty often: Sometimes it's a dark gray, sometimes a noticeably lighter shade.)

Bottom line - every lot of powder is likely to be different to some small degree. The difference drift may or may not get larger over time.

[LynnJr]

Powders have a 10% window on them for the public and a 20% window for the major manufacturers.
Powders are stored in water then taken out dried and compared to the newest batch made.
If it falls within the window it goes to the general public. If it doesn't it goes into canisters for the big manufacturers.
The reason for the changes in most manuals is do to the freebore of the chamberings.
Google alliant unique stored in water and it's on page 13 of the pdf file.
If your regular load is 50 grains a new batch can vary 47.5 - 52.5 and still use the same label.