[Unclenick]

As I said, the stability calculator tends to give lower-than-actual stability factor numbers for .22's. I don't know why, and that's why I wouldn't rely on it without testing. It is an estimator based on Don Miller's modifications of the old Greenhill formula to bring atmospheric conditions and velocity into the equation, and is not a true direct stability calculation (which is immensely complex and requires data on the projectile not commonly available; center of mass location, for example).

The fact the estimator's number is low does not bode well for pinpoint accuracy though. It also means any slight error in muzzle crown or rifling symmetry or bullet straightness in the case will tend to have their effects exaggerated in the group size. In other words, gun condition and care in loading will matter more than for a shorter bullet. You may benefit from neck sizing rather than full length resizing.

I also noticed the V-max in Hodgdon's data. Your Partition should actually do a little better than that. I think I'm going to have to write Don Miller and see what thinks is happening?

Good luck with it.

P.S. You're likely measuring bullet length just fine. Not a lot of options there.