Powder that is 10 to15 years old should you use the older manuals from back then or could you use today's new manuals with the older powders?

Thanks in advance!

Powder makers go to great lengths to ensure that powders are consistent.

10 to 15 years isn't any length of time to properly stored powders.

Now cases and primers do change more, not in the last 10 to 15 years, but many decades ago.  Don't use 1930s era data for example, unless you can verify it with some thing much more recent.  Yes, that means be careful with those Elmer Keith loads.  Cases were of greater volume back then, and primers were different.

If it was made in the 21st century, any 21st century manual should give good, safe data for loading it.

I would push that back 2 or 3 more decades, with the caveat that some of those older manuals were a bit less than conservative.  Doesn't mean that their use will result in a catastrophic event, but that continued use will be hard on the gun.

New powder is fine, older manuals might have a different starting and max load charge.  Don't be the guy that looks at the max charge and loads 1000 rds with that charge then go shooting and find out they're too hot, then post a sad thread on it in Reloading forum

Work on a ladder of loads from min or 10% under max to the listed max and go at it

10 to 15  years is not that long ....  it will be fine

I have manuals that go back to the ‘60s. I don’t have powder that old , but I do feel that if you can approximate the age of the powder to manuals of the same time, it’s a safe bet.

Plus, depending n the direction a powder manufacturer wants their product to be used, there may be loads listed in older manuals that are not in newer editions. Doesn’t mean that suddenly the powder is unsuitable for a particular caliber/bullet combination, just that testing is pushing towards another application.

As mentioned start at the low end, and work up to what safely works for your application,

This is always the best policy!  Never rely on ant manual's max load.  It might be too hot in your firearm.

That said, I keep old manuals and age-date my powder.  Some of it in less used powder numbers go back to the '70s-'80s.  The starting and ending loads, estimated pressures and velocities are different, even in the same spec test barrels.  That suggests to me that formulations may change a bit over time.

In short, use the manuals as a guide, but always work up.  If the powder is old and you have the corresponding manual, don't exceed its max listing, even if lower than in your current manual.  That way you err, if at all, on the safe side.

Thank you all for the help!

The key thing to remember........ballistic lab testing equipment and procedures got much better and a more accurate picture.  They found they were often off the mark on pressure hence the dialing back of max loads of yore.  


So to reiterate....start low work up and I would stop at the current max not the old book max.   Then again, I am not a full speed ahead junkie.  

Had some 1980 pistol powder and compared it to 2004-2005 powder with the same bullets, cases, primer type and velocity was within 5 fps. Same thing with a rifle powder tested some 20 years later and velocity was withn 10 fps.  Depends on if the storage conditions of older powder and that it hasn't deteriorated. Lots of older manuals have bullets that have changed over the years and modern manuals may be more reliable?

I still have my old manuals from back in the late 70's/early 80's.

Good thing, too.  Helps me find loads for some of those shotgun powders I have in the pistol cartridges (not .40 or .357 SIG - not developed back then).  I haven't tried to load any of the Greed Dot in .45 acp but I've got the old load data in the Speer books.