Been reloading for a few years, and I reload a lot of shotshells, and I have found that the manufacturers websites (Hodgdons, Alliant, Winchester, Remington, Barnes, Sierra, etc) are the most up to data source I've found. I have found some of the troubleshooting issues not so good on those sites. Your ATA magazine may have some loads published as well. I hesitate to use any recipe found on this wonderful internet without some verification from a trusted source - Anyone can make up something and post it, so verify if it's not a trusted source.
Forgive me, I have to say this:
I know you're already aware of this, but be sure you NEVER improvise with components. If the recipe you're loading calls for a Remington STS hull + Win209 primer + a REM xxx wad + 20 gr. of Hellfire Powder, don't swap ANY of them for a product that isn't specifically declared "equivalent". Pressures can spike from something as innocuous as a different wad or hull, and results may be harmful to your health and shotgun! I saw a gun severely damaged by exactly that scenario (according to the owner/loader). Most shotshell loads don't leave enough room for double charges of powder, but it can happen, so pay attention.
Components are tough to find right now, especially Hodgdons powders (in Florida and Indiana anyway), so I am switching over some loads to Alliant powders as they seem more available. Noblesport primers, number 209/686 have been declared officially equivalent to Win209 primers, and my testing backs that up from a target breaking view. If you can find them and not the Win209's, I would not hesitate to use the Noblesports. With a proper recipe of course.
Enjoy and good luck!
