.220 Swift Improved (P.O. Ackley Data) Reloading Data
Warning! Notes: Ballistics are not much superior to the standard cartridge unless it might be with relatively heavy bullets with slow burning powders. Standard twist: 14". (Handbook for Shooters & Reloaders/Vol. 1 - P.O. Ackley, 1962) NOTE: USE THIS DATA WITH EXTREME CAUTION
Be Alert: Publisher cannot be responsible for errors in published load data.