Will loading old powder vs new powder change the charge weight?

[A2theK]

Just ran out of the 1968 powder and dumped in the 2021 powder. Will the VOCs change the charge that much for blasting ammo? Old stuff works fine. New stuff is very aromatic.

Silly I know but let me know.

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[P7M13]

What specific powder?
Density and energy may have changed, so cannot say.

 

[oremike]

No one can say for sure. Shoot it and find out then adjust accordingly.

 

[DizzyJ]

The answer is…..
Maybe.

 

[gmerkt]

I've toyed around with this idea. I had some circa 1970-something Unique that was given to me in 2001. Out of curiosity, some years later, I compared it to some newly purchased Unique. I assembled exact duplicate loads of a given cartridge, only factor being different was the age of the powder defined by the two distinct lots. My notes are not at hand, but I recorded a difference in velocity of something like 6 percent less in the older powder.

Bearing in mind that the manufacturers sometimes alter the formula of a given powder, and Unique was one. Again, I don't have my notes handy and I don't recall if my newer lot of Unique was the Alliant reformulated version. Which by itself could result in a variation.

As to differences in weight/volume of older vice newer powder. My theory is that powder dries out some over time. Which can result in a slight loss of weight. This makes comparisons of weight/volume difficult for most reloading hobbyists. I also lean toward favoring the theory that as powder dries out, it's possible that it loses some of its energy content and that alone could explain a loss of velocity. It likely also explains the loss of aroma.

I would say this as a general rule. If you've been loading your old powder right up to maximum recommended levels, it would be best to reduce the same charge of a newer powder. Then work up. A chronograph comes in handy for this. If you haven't been loading the old stuff at max loads, you will be less apt to have problems.

 

[A2theK]

Thanks peeps. It is BLC-2 powder from 1968 and 2021 loaded at 26.5 for a 55 FMJ. I will let you know how it goes. I have a crono, but probably won't use it. This is bulk loaded ammo for rock pit fun. I will watch for pressure issues.

Thanks again

 

[A2theK]

I've toyed around with this idea. I had some circa 1970-something Unique that was given to me in 2001. Out of curiosity, some years later, I compared it to some newly purchased Unique. I assembled exact duplicate loads of a given cartridge, only factor being different was the age of the powder defined by the two distinct lots. My notes are not at hand, but I recorded a difference in velocity of something like 6 percent less in the older powder.

Bearing in mind that the manufacturers sometimes alter the formula of a given powder, and Unique was one. Again, I don't have my notes handy and I don't recall if my newer lot of Unique was the Alliant reformulated version. Which by itself could result in a variation.

As to differences in weight/volume of older vice newer powder. My theory is that powder dries out some over time. Which can result in a slight loss of weight. This makes comparisons of weight/volume difficult for most reloading hobbyists. I also lean toward favoring the theory that as powder dries out, it's possible that it loses some of its energy content and that alone could explain a loss of velocity. It likely also explains the loss of aroma.

I would say this as a general rule. If you've been loading your old powder right up to maximum recommended levels, it would be best to reduce the same charge of a newer powder. Then work up. A chronograph comes in handy for this. If you haven't been loading the old stuff at max loads, you will be less apt to have problems.

Yes thank you and this is my theory too.

 

[Caveman Jim]

For plinking, I surmise that the older powder will be fine. Good luck.

 

[03A3Sporter]

I used a lot of old inherited H4895 many years ago, finally used it all up just recently in fact . The powder worked fine and never caused any problems . Just out of curiosity I chronographed some of those loads and found them to be within 25 fps of loads that were made with a bottle of new H4895.

Having said that there are a lot of variables and also please keep in mind that UNLIKE black powder which can literally can last forever with no degradation when stored properly. Smokeless powder does break down over time and can become unstable / unsafe . It doesn't mean it will happen in 20 years or even 70 years , but I would most assuredly use caution with any smokeless ammunition that is over 70 years old at this point.

I have started running through my supply of WWII USGI 30-06 because some of it is showing its age at this point , even though it has been properly stored in a climate controlled environment some of it is starting not to go bang. Additionally I have USGI ammo made in the 1960's and 1970's that can take its placed in the emergency rotation .

Just some food for thought .

 

[Hemlock]

I've toyed around with this idea. I had some circa 1970-something Unique that was given to me in 2001. Out of curiosity, some years later, I compared it to some newly purchased Unique. I assembled exact duplicate loads of a given cartridge, only factor being different was the age of the powder defined by the two distinct lots. My notes are not at hand, but I recorded a difference in velocity of something like 6 percent less in the older powder.

Bearing in mind that the manufacturers sometimes alter the formula of a given powder, and Unique was one. Again, I don't have my notes handy and I don't recall if my newer lot of Unique was the Alliant reformulated version. Which by itself could result in a variation.

As to differences in weight/volume of older vice newer powder. My theory is that powder dries out some over time. Which can result in a slight loss of weight. This makes comparisons of weight/volume difficult for most reloading hobbyists. I also lean toward favoring the theory that as powder dries out, it's possible that it loses some of its energy content and that alone could explain a loss of velocity. It likely also explains the loss of aroma.

I would say this as a general rule. If you've been loading your old powder right up to maximum recommended levels, it would be best to reduce the same charge of a newer powder. Then work up. A chronograph comes in handy for this. If you haven't been loading the old stuff at max loads, you will be less apt to have problems.

Last year I did the same comparison as you, only with 2400 in 357 mag. I came to the same conclusion. Powder dried a little? Maybe crimped differently?
With a new can of powder, just back it off a little and try. Better safe then sorry.

 

[Mark W.]

New powder will be fine using loads from new books.

 

[ma96782]

I'd say that the biggest factor would be that....
"Storage Conditions" matter.

I doubt that the Mfns are really into changing the formulas and retaining the same names. For liability reasons. AND, for the record.....I'd also add that, Lot Numbers can/will also matter.

Aloha, Mark

 

[gmerkt]

I doubt that the Mfns are really into changing the formulas and retaining the same names.

It's true. Using Unique for example. Hercules reformulated it in 1960. After Alliant took over, it was reformulated again in 2001 to be cleaner burning. This reformulation was widely publicized in gun mag advertisements at the time.

The manufacturers probably don't always announce changes in formulation. So long as they are sure that burning characteristics have not changed significantly in the process. I do not know but suspect that IMR powders, at least some of the extruded powders that I use, were reformulated when DuPont sold to IMR in Canada and the entire process was moved. IMR 4895 powders made in Canada look different than the old version made in the US, grains not as shiny. Which may or may not mean anything. Reformulation doesn't mean they've thrown the baby out with the bathwater.

.I'd also add that, Lot Numbers can/will also matter.

Absolutely they can matter. An example in my experience, IMR 4064 can vary widely from lot to lot. I've had a difference of over one grain in weight due to variation of powder volume from one lot to another.

I think these small variations, whatever the cause, are pretty much covered with general recommendations in every manufacturer's data that says to start low and work up. Or they sometimes used to say things like, "Reduce your initial charge by (some percentage) from our recommendation." I think the old DuPont data had boilerplate like that.

 

[Dr Prepper]

I used a lot of old inherited H4895 many years ago, finally used it all up just recently in fact . The powder worked fine and never caused any problems . Just out of curiosity I chronographed some of those loads and found them to be within 25 fps of loads that were made with a bottle of new H4895.

Having said that there are a lot of variables and also please keep in mind that UNLIKE black powder which can literally can last forever with no degradation when stored properly. Smokeless powder does break down over time and can become unstable / unsafe . It doesn't mean it will happen in 20 years or even 70 years , but I would most assuredly use caution with any smokeless ammunition that is over 70 years old at this point.

I have started running through my supply of WWII USGI 30-06 because some of it is showing its age at this point , even though it has been properly stored in a climate controlled environment some of it is starting not to go bang. Additionally I have USGI ammo made in the 1960's and 1970's that can take its placed in the emergency rotation .

Just some food for thought .

Interesting thread. I had bought some older powder i was kinda questioning how old it was. And was waffling on using it. Some smell fine others no smell. I guess if i smelt it... I must dealt it. (Its a trap!)
Just last weekend i finally got to pew off a test of some 4756 i think it was. The old discontinued stuff that came in a green 8oz metal can.
(The stuff everyone is looking for still to this day) and man alive!i can see why. It shot about nothing but half dollar sized 5 shot groups @ 20yrds. Never seen a powder that good before, Not for 10mm. And sadly i wish i had more now .

Ive always been very apprehensive to use old powder. But idk mind is changing.
Sadly i cant compare to a newer or older lot. So im just rambling on over here as usual. (Dont mind me!)

 

[03A3Sporter]

This is the truth and some of my favorite "pet loads" come from a book that was written in 1995 IIRC. Aside from the fact that H450 (RIP) and A3100 (RIP ) the A4350 loads still hold true all these years later .Manufacturers do not change power burn rates for a formulation , it just doesn't work that way.

I'd say that the biggest factor would be that....
"Storage Conditions" matter.

I doubt that the Mfns are really into changing the formulas and retaining the same names. For liability reasons. AND, for the record.....I'd also add that, Lot Numbers can/will also matter.

Aloha, Mark

 

[Certaindeaf]

Interesting thread. I had bought some older powder i was kinda questioning how old it was. And was waffling on using it. Some smell fine others no smell. I guess if i smelt it... I must dealt it. (Its a trap!)
Just last weekend i finally got to pew off a test of some 4756 i think it was. The old discontinued stuff that came in a green 8oz metal can.
(The stuff everyone is looking for still to this day) and man alive!i can see why. It shot about nothing but half dollar sized 5 shot groups @ 20yrds. Never seen a powder that good before, Not for 10mm. And sadly i wish i had more now .

Ive always been very apprehensive to use old powder. But idk mind is changing.
Sadly i cant compare to a newer or older lot. So im just rambling on over here as usual. (Dont mind me!)

Some of the best powder I ever used in 9mm/.45acp was TopMark.
This was 40 years ago and it had been discontinued for decades when I loaded it.

 

[Dr Prepper]

Lol. Dang... Ok then.

 

[Dr Prepper]

Some of the best powder I ever used in 9mm/.45acp was TopMark.
This was 40 years ago and it had been discontinued for decades when I loaded it.

Wait.. a.. minute.. Did they even have 10mm 40 years ago? man! I'm getting old! Lol.