Old powder

pete5409 · November 1, 2022, 01:36 PM

I purchased an old can of Du Pont powder. It looks dry and smells OK. I want to try a few loads with it but don´t know whether to base recipes on an old Du Pont reloading manual or stick to Lyman´s recommendations in the 50th edition?

Marco Califo · November 1, 2022, 02:01 PM

You can find old IMR load data here:
http://www.castpics.net/LoadData/Freebies/RM/IMR.html

RC20 · November 1, 2022, 02:49 PM

I would treat it as an assessment case.

1. How Old does the container look to be (ie, era, Can, Lined Cardboard or plastic?)

2. What era is your old IMR manual

3. If needed, got toe the above IMR site.

If there is any doubt go with the lowest loads.

I have used some pretty old powders and I have thrown some away based on the smell and appearance.

**Unclenick** · November 1, 2022, 05:01 PM

I would ignore the old manuals, particularly if the loads exceed the current data. Many old manuals were published in an era before actual pressure testing was the norm, and loads were determined by the gross vagaries of pressure signs apparent on loads fired in production guns that could, at times, be atypical of most other guns out there. Modern load development is done in SAAMI spec pressure and velocity guns that have tight tolerance minimum chambers in order to present a worst-case pressure situation. That is a much more reliable approach.

Stick powders can last a long time if they are kept at cool or modest temperatures. If you sealed them in plastic and put them in your freezer, they would last a good number of centuries. The British military limits them to 45 years in stockpile storage (loaded ammo kept in cool-ish bunker temperatures, but still safe to issue), while they limit spherical propellants to 20 years in those same conditions. The latter suffer breakdown faster. In typical basement environs, stick powders can go well beyond that 45-year time frame. 60 to 100 years would not be outside the realm of possibility.

Sure Shot Mc Gee · November 1, 2022, 10:58 PM

Being a old school reloader I have both new and old powder charging literature to research. As suggested prior. Safest way to home reload is stick to current reloading publications. (best advice)
As for allot of us we over the years experimented and developed charges for our own use. To make changes to those tried & true powder recipes due to a newer powder publication saying different. For my use? I usually don't re-measure. I kinda like to push the boundaries of high velocity. Duplex loads Surplus powders items most home reloaders would not bother investigating.

mgulino · November 2, 2022, 06:56 PM

Picked up several pounds of old DuPont powder from my son-in-law earlier this year. His friend’s father had passed away and they found it while cleaning the garage. A note in a can of brass was dated 1974, so I assume the powder was about that old. Someone on another forum sent copies of pages from an old copy of a manual, Lyman I think. I loaded up a few 39 sp…stayed on the low end. Shot them in a GP100 in .357. They were slow but functional.

November 1, 2022, 01:36 PM	#1
pete5409 Member Join Date: March 26, 2008 Location: Mexico Posts: 37	Old powder I purchased an old can of Du Pont powder. It looks dry and smells OK. I want to try a few loads with it but don´t know whether to base recipes on an old Du Pont reloading manual or stick to Lyman´s recommendations in the 50th edition?

November 1, 2022, 02:01 PM	#2
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,614	You can find old IMR load data here: http://www.castpics.net/LoadData/Freebies/RM/IMR.html __________________ ............

November 1, 2022, 02:49 PM	#3
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	I would treat it as an assessment case. 1. How Old does the container look to be (ie, era, Can, Lined Cardboard or plastic?) 2. What era is your old IMR manual 3. If needed, got toe the above IMR site. If there is any doubt go with the lowest loads. I have used some pretty old powders and I have thrown some away based on the smell and appearance. __________________ Science and Facts are True whether you believe it or not

November 1, 2022, 05:01 PM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,122	I would ignore the old manuals, particularly if the loads exceed the current data. Many old manuals were published in an era before actual pressure testing was the norm, and loads were determined by the gross vagaries of pressure signs apparent on loads fired in production guns that could, at times, be atypical of most other guns out there. Modern load development is done in SAAMI spec pressure and velocity guns that have tight tolerance minimum chambers in order to present a worst-case pressure situation. That is a much more reliable approach. Stick powders can last a long time if they are kept at cool or modest temperatures. If you sealed them in plastic and put them in your freezer, they would last a good number of centuries. The British military limits them to 45 years in stockpile storage (loaded ammo kept in cool-ish bunker temperatures, but still safe to issue), while they limit spherical propellants to 20 years in those same conditions. The latter suffer breakdown faster. In typical basement environs, stick powders can go well beyond that 45-year time frame. 60 to 100 years would not be outside the realm of possibility. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

November 1, 2022, 10:58 PM	#5
Sure Shot Mc Gee Senior Member Join Date: January 2, 2012 Location: Minnesota Posts: 3,876	Being a old school reloader I have both new and old powder charging literature to research. As suggested prior. Safest way to home reload is stick to current reloading publications. (best advice) As for allot of us we over the years experimented and developed charges for our own use. To make changes to those tried & true powder recipes due to a newer powder publication saying different. For my use? I usually don't re-measure. I kinda like to push the boundaries of high velocity. Duplex loads Surplus powders items most home reloaders would not bother investigating.

November 2, 2022, 06:56 PM	#6
mgulino Senior Member Join Date: July 2, 2017 Posts: 202	Picked up several pounds of old DuPont powder from my son-in-law earlier this year. His friend’s father had passed away and they found it while cleaning the garage. A note in a can of brass was dated 1974, so I assume the powder was about that old. Someone on another forum sent copies of pages from an old copy of a manual, Lyman I think. I loaded up a few 39 sp…stayed on the low end. Shot them in a GP100 in .357. They were slow but functional.