The legendary P, O, Ackley asked the same question when confronted with the .263 Express, a precursor to the .260 Remington, by Ken Waters. He was of the opinion that you'd get better veolcity due to the larger bullet diameter. History as shown however that velocity isn't what the .260 is about, and why give up what the .270 Winchester already provides. So the question is once again, why bother?