Has anyone tried or have any info on using WW571 in the .22 Hornet with 37gr Calhoon bullets, or similar weight bullets? My Hornady manual(1978) shows Unique and H240 data with a 40gr bullets, and Calhoon gives data using Blue Dot. I'm not restricted to WW571, it just that I got about 4 lbs of it originally for a heavy 12ga duck and goose load but since lead shot is not allowed over water anymore I thought it might work in the Hornet. My burn rate data shows WW571 to be right in there with H240 and Blue Dot and definitly a lot slower than Unique, so with the lighter 37 gr bullet.....?

Carlos: Why don't you swap that 571 to some 20 gauge or magnum 12 shooter? It's no longer made, and was one of the best for both 12 and 20 heavy loads. I'm sure someone would like to have it. I'd like to have it myself, but it wouldn't be practical to get it to me in Texas.

I have a Hornet (K-version), but have never tried anything like WW 571 in it. There are a lot of newer powders that are reported to work well, but the old standbys of Hercules 2400 and IMR 4227 do well.

FWIW, I use WW680 and 40 grain Nosler BT's in my Hornet. Not exactly the same but in the ballpark. Could not be happier with this combo, but will have to switch powders soon because WW680 was discontinued several years back.
Try it, you may find your gun likes it. Four pounds of WW571 would just about last a life time when filling those little Hornet cases.