Powders DO vary from batch to batch !

[SASS#23149]

During a reloading session the other day,I emptied my buddys' W748 out of the hopper to put mine in for my shells,and just out of curiosity and for safety,re-checked the dump.
WOW,almost 3 grains difference between the 2 jugs of powder.
Now,they were several years apart in age,and who knows what changes the mfgr. had made along the way,but the point is SAFETY FIRST.
Check different batches of powder,don't just add more from a new jug.

to clarify,my W748 dumps were a full 3 grains heavier than my friend's powder was.yikes.

 

[mmorris]

This makes me wonder if you only have new powder because you just got started, how useful is historic load data from manuals several years to several decades old? Is it advisable to match the powder mfg year to the manual year, and then check the mfg's website to verify no changes since it was printed?

I really like my fingers.

Don't want to blow them off cause the mfg had to change the formula in 2006 and my book is for 1986.

I understand that the story is about different powders having different volume/weight relationships, hence throwing different weights until adjusted. But it seems that powder requirements do change sometimes (in reality, not just the Lawyer's mind), and that's my concern.

Mike

 

[ClarkEMyers]

Right to wonder and for my money it's true - new powder go with the newest book.

Right to wonder and for my money it's true - new powder start with the newest book.

There is an argument for loading some powders especially black powder and substitutes by volume.

That said I do have plenty of discontinued powders - from kegs of WAP and 452 from Winchester and pounds of H205 and some others to use with respect given the age of the powder and the data.

Ideally I might not store powders after the manufacturer drops them - they sometimes come back if one can trust them to be the same - but then again if I had a choice I'd settle for all factory ammunition and I don't have that option.

 

[Mainiac]

That is another reason you should always double check your powder measure when adding new powder. On powders I use alot I try to purchase several pounds from the same lot, or a 4 or 8 pound container.

 

[ranger335v]

"Is it advisable to match the powder mfg year to the manual year, and then check the mfg's website to verify no changes since it was printed?"

It is advisable to follow the books suggestion to load down a bit with any change of components, including powder lots, and only move back up if no over pressure indications appear. Done correctly, it won't matter how old or new the data or powder is.

 

[RecoilRob]

This has also happened to me going from batch to batch of the same powder.

But, the weighed charges of the two shot almost identically....even though they occupied different volumes.

Seems like mass is mass and the powder companies do a fine job of making consistant powders....just don't expect lot to lot to be the exact same bulk.

 

[Master Blaster]

This is why you weigh charges for Quality control even after you have set the measure and are loading. This is why the manuals recommend you start 10% below max(with some rare exceptions) and work up.

The 3 grains was part of a max charge of how much??? 26 grains (.223) or 60 grains (300 win mag)??

It could have been a variation in the grain size since the measure is volumetric, or it could have been that your powder had a bit more moisture in it??

Always reduce by 10% and work up when changing powder, primers, or bullets, even if its only a different lot. Always weigh the chrges initially and periodically when loading. Always pay close attention to what you are doing when loading.

 

[243winxb]

Affects on powder over time

As the powder ages it can take on moisture if it is not stored in a Controlled Environment. Changes in heat and humidity can add moisture/weight to the powder . But 3gr does sound like a lot. I would think weighing the powder from the measure at the start of reloading would be light , compared to the last powder drop that would be heavy. The powder packs with the movement of the powder measure. This is why you should throw at least 10 to 20 powder drops before starting to load. More so with ball powders.

 

[USSR]

During a reloading session the other day,I emptied my buddys' W748 out of the hopper to put mine in for my shells,and just out of curiosity and for safety,re-checked the dump.
WOW,almost 3 grains difference between the 2 jugs of powder.

This is a powder measure issue, not a powder issue. Take two guys who operate the same powder measure in a slightly different manner with the very same powder and you are likely to get a variance in thrown charge weights. Guys who weigh all their charges have no concerns.

Don

 

[243winxb]

This is a powder measure issue, not a powder issue. Take two guys who operate the same powder measure in a slightly different manner with the very same powder and you are likely to get a variance in thrown charge weights. Guys who weigh all their charges have no concerns

Very good point. So true

 

[RavenVT100]

If you didn't weigh each charge then there's no way you can know for sure whether your tests were accurate. Shooters need to approach reloading from a scientific / QC standpoint. The scale gives real data; throwers are designed to be thrown consistently each time and two different people are not going to be able to throw the same charge reliably one after the other.

 

[Peter M. Eick]

Also powder tends to give off volities and "drys out". If your was a new can and his was a couple years old, I could easily see the variation.

 

[Der Verge]

Somewhere, in one of my OLD reloading manuals, there was a section where the author did a little experiment. It was the measurable difference in charge when comparing powders of different moisture. Moisture was gently cooked out of one batch, to simulate aging. I forget what powder, but I beleive the charge was for a .30-06. I am not sure of the exact charge, but it was somewhere in the area of 52grains. Anyway, a charge of the "fresh" powder was weighed, the an appropriate dipper was found for that weight charge. Therefor, the weight was converted to volume. Then the dipper was dipped in the "aged" powder, and that charge was put on the scale. The "aged" charge did way right around 3 grains more. When I find the article, I will scan and post....

Remember, 3 grains of water is only 1 / 151.84oz..........