[old roper]

Corrections Cop

The 270 Ackley mag/7Ackley mag case is 2.450" long ( 7mag case length 2.500") and rim to start of shoulders is 1.9075" vs 7mag @ 2.040" and they formed those cases from the 300 H&H since it was before the 7mag case out 1962.

You have to set the shoulders back .1325" using 7mag case. One reason they used the 300H&H case is you could cut case at the start of the neck and length be 2.479" and the body dia was smaller so you didn't have to form shoulder. All you had to do is form a neck and could do that pretty easy so IMHO pretty easy wildcat.

One problem using the 7mag case you can buckle the shoulders setting back that much using 7Ackley Mag die vs using some type of form die.

If it was me and someone had dies I'd have GS make chamber cast and send that along make sure reamer used for those dies was the same.