I'll go #2. That sounded wrong.
We could raid the Wheelgunners for members, and include traditional blackpowder shooters.
But since Single Action Shooting Society (SASS) is probably the copywrited name of a business, I think the more general term Cowboy Action Shooting would be better.
We should also open it up to Civil War re-inacters and buckskinners, in fact everyone who is interested in American shooting before WW1.
"...women in politics or in public roles should grow skin like a rhinoceros,” Hillary Clinton said, quoting Eleanor Roosevelt. “I think there is some truth to that.” So, she did.