The 13-72 is perfect on 27" in B (I prefer to keep 'em tight) but easily downtunes to A or Ab and retains a lot of good tension, perfect for palm-muted, galloped, string-skipped thrash that I don't play at all

Used it on a 24.75 inch scale Les Paul and tuned it real low (as far as drop G#) and it's still got enough tension and tightness