I'm preparing to work up some handloads for .357 Magnum. I want to use Hornady 158 grain JHP, Federal 200 magnum primers, Federal and PPU cases (not mixed), and Accurate #9 powder. I am seeking counsel on how to proceed with a start load with that bullet.
Hornady 9th manual: Start 9.7 grains, max 11.5, magnum primer, Frontier case, Python 8".
Lyman 49th manual: Start 13.4 grains, max 14.9, magnum primer, Federal case, 4" test barrel.
Hodgdon website: Start 12.4 grains, max 13.8, magnum primer, Winchester case, 10" test barrel.
What concerns me is the wide variation among the starting loads.
What would the handloaders here with superior experience choose?
I've been handloading for 50 years, still don't know everything, and probably never will!
You are overthinking it. Any manual starting load is safe, you simply work up from there looking for pressure signs. Every gun will produce a different velocity, if that matters, change powders if the one you choose is not a fast as you demand.
As to safety. There is only one place on the planet that a safety requirement is made as to a product, any product. If you buy Round Up to kill wees, or Dove to wash your dishes, or AA7 to load ammo, only the one company that creates it must file a pile of documents do make sure it is safe when directions are followed. The safety data sheets are what a manufacturer or importer files to ensure the feds that the product is safe.
Only the manufacturer is on the hook for that, none of the people like me or Nosler, or Speer or someone else who publishes recommended load recipes has that obligation.
So, if your question is about safety and starting loads, you do to the site that produces it. If if is a Hodgen powder, you go to Hodgen. If it is Alliant, you go to their site.
Hornady for example does not make powder, they are just giving their experience on one day at one elevation at one temperature with test barrel that will not fit your gun. So, their data will always be different. Not much chance of them being the same.
Accurate is Hodgen, you use their data, they are the only one on the planet that files the safety data sheet for that product.
https://hodgdonpowderco.com/wp-content/uploads/2023/06/2022-Accurate-Double-Base-St-Marks-SDS.pdf
Read it for yourself.
Then you go to there reloading data, it will be consistent with their safety data. Plug in the closest bullet and there you are, the most accurate and safest data you can find. Other manuals are just adding their results from another day, another test barrel, another elevation, another temperature. They may be helpful they may not be, but they will not be safer or based on as much data and testing as the maker of that power. Your results are here:
Personally, I like H110 or W296, same powder, and the Hodgen site tests those as well, but their data is only as test data like any body that sells a manual. This is my choice. Both are within safety levels, I just like the 110 because at the same pressure, noise and recoil, the 110 is going to send the bullet a little faster, 1,591 fps vs 1,367 fps. Does it matter? Probably not.
Just for your information. Always go to the company that is required by federal law to file the product safety data sheet, then go from there to create the best loads for your guns.
Not for me to judge, but I believe I'm somewhere north of 200,000 successful rounds loaded, likely 97% of them being handgun and I've been quite happy with how my experience has worked for me. Surely hundreds of thousands less than some competition shooters, but possibly more than the average tinkerer?
