I have an acs 62" 60@27 and I shoot Beaman 500mfx cut to 28" with 250 grains up front. I originally bought 400's for it , but had to put 350 grains up front and cut to 29.5" to bare shaft. I would try the 250, I shoot them out of my 75# hummingbird w/ 300 grains up front and cut to 28". I draw a solid 27". Just what works for me. Also, I bareshaft towards the weak-side. When you add feathers it will stiffen up the shaft. Plus, a weaker shaft is more forgiving of a not so perfect release.