Keith,
I’m guessing that the manufacturers of shotgun ammunition know, exactly, what pressure is produced from every single loading they produce. They know exactly which components affect that level of pressure, and why. I’d bet there is far more testing of loaded ammunition than we would have guessed.
That said, there is exactly zero evidence to suggest that sharing that information with the end user would be a benefit to them. Leaving the answer to the question at “below SAAMI max” puts any and all responsibilities for the use of that ammunition on whoever bought it. They tell you straight up it could be the hottest stuff that they can get away with loading, and it is totally up to the consumer to make sure his equipment is up to it. They will be no “he said” in a courtroom when somebody guesses wrong on what they can get away with on their antique gun.
If somebody has a requirement for low pressure ammunition, they had better be sure they source low pressure ammunition for that requirement. I am stunned at the guys who are willing to take a guess that some off the shelf ammunition will be what they need for their old gun. Guys who I figure should know better, do it right here, all the time.
Best,
Ted
