I still use .303 for my Krag scout but use the real .30-40 for my Krag Constabulary. The headspace or chambers are different enough that the only way I can use my handloads in both rifles is to full length resize them which is overworking the brass. I just neck size each with a .308 Winchester sizer die and using .303 for one and .30-40 for the other keeps it simple. Using the same load otherwise. Haven’t done a whole lot of load development yet. The steel in my yard doesn’t stand a chance so they can’t be too bad.