Started to shoot Dad's longbow that has been collecting dust. Thought I'd try some cedar shafts he had laying around as well. I was shooting one that had been fletched with a 145gr fieldpoint. I'm getting a severe fishtail with the tail end kicking right until about 15yards when it straightens out. I'm right handed shooting a 55# @ 28". Granted my form and release need a lot of work but trying to get the right spined arrows. Am I under or over-spined?