velocity spread?

[Jack]

Velocity spread can vary with the load and cartridge, as you've seen. Often, a low extreme spread is considered a sign of an accurate load - although I'm not sure that's really true for typical hunting. For very long ranges, where 100 fps may cause a slightly different drop at, say, 1000 yards, yes, but for typical under 400 yard shots, extreme spread won't matter much.
A low extreme spread is a sign of consistency in a load- just don't make too much of it.
It's worth keeping in mind that when the 222 cartridge was in it's benchrest heyday, it was famous for 2 things- extreme accuracy, and huge extreme spreads in those same bugholing loads.
I would consider 10fps to be a low extreme spread- something like 20-30 might be more typical. Anything over 50 or so, I'd consider high.