It's an incredibly useful powder, even for many rifle calibers. It's especially good for cast in rifles, with published loads all the way from 218 Bee on up to 45-70 (and probably higher).
Also check out this cool article where C. E. "Ed" Harris describes his adventures with a leftover caddy of Red Dot, and how he found a highly repeatable load for shooting most any military service rifle in .30 cal or larger: https://www.hensleygibbs.com/edharri...The%20Load.htm