Dropped by my favorite gun store today, it's this big, unorganized place full of the most eclectic collection of old guns, old reloading stuff and fishing and boating gear and I love it. The old man must be well up in his 80s, but is still sharp and he's probably been in business there since the 50s maybe longer.
Anyway, I went in there in hopes of some new old stock SR4756, no luck, but as I'm looking, there's two of the old paper bags like they used to sell powder in up on the top shelf, likely not touched for decades marked Hi Vel #2.
I have some old manuals that have data for this stuff. I've half a mind to go back and make an offer on a bag of it to try it out. Anybody ever used it?