Dad gave me his reloading stuff lately which included some Lyman's Reloading Handbook's. The latest is the 47th Edition dated 1992. How has the components (powder, primers, and bullets) performance increased since then? Is the data in the book extremely outdated? The primary data I care about is for the .257 and 7MM Mag. TIA

Yes it's best to use updated info for newer components but if your using tried&true loads the advice to start 10% under and work up still applies. Example the very famous Skeeter Skelton load for the .44 spl from the 1960s actually came from Elmer Keith in the 1930s.

Lot of new powders available today compared to 1992.

I usually start at the maximum load and work up from there.

Thanks Dave. Until I have the ability to test variable reloads, practice, and test, I'll just stick with what is tried and trued. Hell, I probably can't find/buy the latest components anyway! lol

I'm using a 1975 manual - has lots of old stuff not in modern one.

I regularly use manuals that date back to the 1960's. Some of the old manuals have some really good info in them.

Newer powders that have come on the market since the 90's are not necessarily better than anything form the 1940's. It all depends.

I never use the book version. Everything is online.

I have more faith in lyman data being consistent than most anything else.lyman book and hodgdon online data have proven most accurate and consistent far as pressure and velocity

Seems most agree that the older manuals do have some outdated powders and such, but that's only natural. Over time some powders are going to be discontinued. Generally if you're not in a big hurry the makers of powder will answer questions on a specific load if they are given the specifics. They'll be able to tell you if it is a dangerous load combination. Just send an email. I've got about 50 books spanning 70 years. There is data there that's no longer usable but surprisingly still plenty that is.

The data that is no longer usable, is it because the components are no longer available or another reason?

Data in old loading guides was often developed without pressure test barrels. They used flattened primers, hard bolt lift and other old tricks to determine maximum charges. Once you start seeing these signs you are well beyond safe pressure limits. New guides are developed using pressure test barrels.

Your best tool for developing handloads is a chronograph. Get one.

Remember, these books are guides, they are not the gospel. The information in them was developed in their guns, using the components available at that time. All components will vary in different manufacturing lots, so using YOUR components in YOUR gun will yield different results. The chronograph will tell you this.