I am going to buy a new string for my 60# Samick Spirit II recurve, because the string that came with is is a little frayed at one end. I am going to buy a Brownells Fast Flight plus from 3 rivers archery. I have to measure the string for thier sizing. I measured the string at a little around 57.5 end of loop to end of loop. I thought usually a 60" recurve would take a 56" string. Did the string strech? Should I buy a 56", 57" or 58". I am leaning toward the 57", can a string strech 1.5 inches over time? Thanks for the help fellas.