I have been reloading for 20+ years. I recently bought a mixed batch of powders from a good friends estate. I knew him very well. A lot of the powders were from the 70s like W296,W571, H414, SR 4756, Dupont PB, IMR 7625 and some others. I have (2) Hodgdon Annual Manuals that I normally reference but many of these are not listed.
Where can I find more information on these powders as in which cartridges each of these would be best for? I have several reloading manuals that I reference but to find all of these powders would take some time.

Cant help you on where to find the info. Did you try to google each powder? The W296 is a magnum pistol powder. I just bought a 44mag and was looking up some of the powders that i can use for it and that was one.

A very helpful thing to have is a burn rate chart. That way one can approximate what a powder can be used for and in what qualities. Then work up from there. Not worth doing if ya only have a pound of the stuff in most cases. But well worth it for larger quantities.

hodgdon has info on H414 and W296 in the reloading data center

W296 is magnum pistol powder

H414 is rifle powder 22-250 and 243 come to mind

IMR 7625 , IMR 4756 , W571 look in lee modern reloading 2nd edition they all have listings in the heavier bullet 9mm loads

DuPont PB PB being the symbol for lead I think it is the same as IMR PB

I'd just get a hold of the manufacturer and ask for some data for whatever calibers you want to load for .

I have two. But many of the older powders are not listed.

I loaded 296 in the 410 for years.

But only if he wants the most accurate and reliable data!

PM sent

A burning rate chart is in my 30-year-old Speer book. All those powders are in my sierra and speer and Hornady books, since they are over 30 years old. I could copy some pages for you if it would help. Just let me know

With powder that old, don't be surprised if you get erratic performance from it. I used up some 4831 that was at least 30 years old and the bullet impacts were all over the paper. Best group was about 36 inches

I went back and sniffed the remaining powder. Smelled very pungent. Almost like someone had poured ammonia in the bottle

I had a 12 lb steel keg of H4831 2ed batch from WWII that I used in my 270, 30/06 and 7mm Mag that I had outstanding accuracy with. But, if it was not stored properly I would be concerned as well.

I will go through my books maybe I have a Speer manual. Thanks

Two good links for reloading data.

http://www.hodgdonreloading.com/

http://www.castpics.net/LoadData/Freebies/RM/winchester.html

I dont think W296 from the 70's is the same powder sold today. I think I would call folks like Hodgdon. They distribute all winchester powder now and also IMR powder. They also do all the reference testing for each new lot. Ask them if load data is still the same.