On Easton's site when I pich recurve bow, 125gr point, 44-48#'s and a 28" arrow it gives me - 2212, 2213, 2115, 2018 spines ranging from .460 to .505.
I just happen to have some 2213's cut to 28" and just tried them. I shoot left handed. Flight is terrible with them hitting right on my target and a bareshaft flys so bad it missed the "block" to the right all together. These are spined at .460. I also have some 2013's some 27" and some 28" I tried them. The 28" bareshafted great. These arrows have a spine of .610 but fly great, which is comparable to a 1916 with a spine of .623