Hope this helps you out. When I got my Crusader from Chad, I bought 65-70 spined arrows cut them 28.25" BOP like all my others, and shot the bow, only to find out I wasn't drawing all the way back. So ineeded to lengthen the arrows so I cut them so I had about a 1/2" clearance when at full draw, which I now have an arrow that is right at 29" BOP. and this made the spine right at the edge with a 125 grain point. So I upped the spine to 70/75 same length, but I can now shoot a 160 grain head. Yes the other arrow shot, but I was gettting erratic results. the increase inspine solved that.

For you, If your arrows ar 27.25" then go down a spine group. I have some 55/60 spined 28.25" POC ready to shoot if you would like to try a couple before you buy a dozen? shoot me an e-mail and I will send them out. I do thik 50-55 will be to weak, but I may be wrong also.