There are Nockturnals you can buy that have all the bushings for every common type of arrow. That is what I am calling universal nocks.I wonder what universal fit is? since most arrows have a different internal diameter and take different nocks unless you buy specific uni-bushings. My PS26, Fatboys, and Vaps all use G nocks because I bought the proper uni-bushings. Sounds to me like the universal fit is .246 and you are using arrows that take a .245 nock.