Over the past couple of months I've been testing out the new Garmin Fish & Hunt Xero X1 crossbow scope, which is mounted on an Excalibur Crossbow Assassin 400 TD. During that time, the center serving on the crossbow string unraveled and since I couldn't find any serving large enough at my local archery shop, I picked up a new string. Having never changed a crossbow string before, I called up Excalibur and they sent me a simple stringing aid and told me it was an easy job. I figured I'd see if th