I think you are confusing the upper and lower wiper rings with the corrugated "filler" ring. The filler ring ends butt together, but they can still expand as they get hot 'cuz of the folds. The upper and lower wiper rings need to be gapped just like a compression ring.
72 Mach 1 - 460, C6
65 Olds 4-4-2, 400 ci, 4-sp
71 Dart Swinger 340 - Project in the queue