TWIST, VELOCITY, AND STABILITY
As velocity falls, eventually bullets become unstable.
The barrel tested here was originally a Stevens 223 Rem, re-chambered to 22-250 by Ken Campbell. I sawed it off to 16.5” and chamfered the muzzle.
Titegroup powder, misc. primers.
5-shot 100 YARD GROUP” is the average of all groups with that load.
The 40 and 53 grain Nosler bullets have plastic tips ~.1” long. Greenhill twist is calculated with and without the tips.
MV is measured with a chronograph; 100 YARD V is calculated using the published BC.