Back in the late 70’s I started loading for shotguns mostly for skeet and trap . And at the time I was enamored with Winchester powders . Used 452AA in the 12 , 473AA in the 20 , 540 in the 28 and 296 in the 410 . Later Winchester brought out WSL and WST for the 12 and I used both , they replaced 473AA with WSF which I then used in both the 16 and 20 . They quit selling 540 and to the best of my knowledge never replaced it with anything . But on the other hand Hodgdon HS-6 is supposed to pretty much be the same thing . Only one from almost fifty years ago Winchester still makes is 296 go figure
