Sawzall... both the 30-06 and and 270 are based off the 30-03, however the 270 having the same shoulder as the 30-06 and appearing later than the 30-06 would place it as being more derived from the 30-06 than the 30-03, besides that, having reloaded both, the case length difference is far less than you claim. Just measure a couple of spent factory cases.