Someone said long range shooting is speed, well many with speed just fall off...

No revaluation, but it's-- speed + weight + BC. ( I would add sectional density for long range hunting)

However, tell that to the guys shooting 45-70s and such out to 1200 yards, with iron sights! Plus they have been doing it for 100 years or so!

A 270 will serve you well, study the published load data, and work yourself up a load. That's what's fun to me, getting the most out of each rifle...

Just for the record, I have a very fine 7mm mag, and a very fine 280AI. I consider my 280AI one of my very favorite rifles, of all my rifles, not just compared to the 7mm mag-- and I love overbores!