If I'm remembering right from my days in machine shops, identical diameters on the hole and plug are considered a press fit. Especially since both are likely to be slightly out of round. We figured an alignment pin needed to be 2-3 tenths smaller to allow reasonably free engagement.
This doesn't even take into account the bullet diameter increase after getting slugged in the butt upon pulling the trigger.
Last edited by Ole_270; 05/21/22.
