One reason your rifle has a 22" barrel is that it was found many rears ago when the standard 270 came out that it shot better in that lenght barrel,than other lenghts. As far a losing velocity,don,t worry about it your only losing about 45fps than a 24" barrel.Just load your loads as if you were from the beggining,don,t need a faster burning powder. You,ll have more than enought to do the job which the cartridge was designed for. vangunsmith