The static spine on aluminum is measure at 28" not full length.I like to bareshaft my arrows to get the best dynamic spine for my bow.Your arrow at 29.5" will be less then .531 because it is longer then 28".Dynamic spine is found whlie shooting and tuning.Hard to say at what length you need for about a .500 spine.Alot of variables involved,point weight,your draw length,string material,arrow length,how the bow riser is cut.I like 2016 arrows,fit alot of bows in your weight range.Might be weak for the ACS,my ACS takes alot stiffer spine then some of my other bows in the same weight range.