. . . good loads have an ES of about 10% or less of max velocity (in your case about 31 fps), and a single digit SD.
31 fps is 1% of velocity - is that what you meant? I've never heard of this "rule of thumb".
MM, you are correct. It's 1%, not 10%. Good catch. Apologies for the typo. I'm not sure if it's an established "rule of thumb", but it is a metric I try to achieve with my handloads because it makes sense to me. I must have heard, or read it somewhere because I don't think I would have come up with it on my own.
