I am installing new piston rings and had to go with oversize filed down to spec because the standard had gaps too big. The ends of the oversize oil expander seem like they are overlapping when placed in the groove. I know they are supposed to compress like an accordion but that doesn't happen readily, instead, the excess length seems to obstruct slider rings that go under and above it. I had multiple incidents where the sliders didn't sit in right precisely because of that and they would even pop out when I was putting the piston compressor around, which is scary because they could go in the cylinder not lodged properly.
Should I clip the expander just a little (e.g. 1/16" or roughly 1-2 mm), with something like small electrical angle cutters to avoid this overlapping?