The 13lb is a reduced power spring for running reduced power loads.
Factory 9mm loads are much stronger than necessary to meet minor power factor.
My 127-129 power factor 147grn 9mm loads will stove pipe with a factory spring.
Factory 9mm loads are much stronger than necessary to meet minor power factor.
My 127-129 power factor 147grn 9mm loads will stove pipe with a factory spring.