What is the difference between an Ion and Ion XE feedneck. I am interested in buying a Lapco Ion XE Ultra Low clamping feedneck. I am currently building a Milsim style Ion for woodsball this summer. I have never own or built an Ion so this will be my winter project. I recently bought the Lapco Ion Body I was wondering if the the Lapco feedneck will fit on a regular Ion breech?