When steel shot was mandated. No real useful data was available. People got together and shared what they where learning. Some website's in the early days, had secret reloading books forums. Where once the gang had vetted you for a while, you got the secret handshake and access to the process was opened up. Some of these guys had their own pressure test equipment or where using a couple commercial ballistic techs with the gear to pressure test the experimental loads. Much of what you see in todays steel shot reloading data started in these experiments. If you can fit it in a hull, someone tried it. Some of these loads are still being used and they have never been in a printed book. A good load is just that, Good. Reloaders with years of experience can and do alter load data to fit what they have on the shelf. If a load calls for a fed209a and there is not a fed209a in 500 miles to buy. Most would substitute another primer they can buy. Trap shooters are always substituting. But most of the base loads they are working off of are low pressure to start with. Clone wads with original wad data is a common substitution. So published data is altered often. My 20ga hunting load is an altered load. Instead of a fed209a I'm running a CCI209, instead of 18.5gr of long shot, I'm loading 18gr, instead of a waa20 I'm using a waa20 clone. One book might list part of this alteration but not all 3. I still feel completely safe shooting it. Because 2 of the alterations lower pressure.
