did that myself once on a 318 Magnum, somehow the skinny lower rail on an oil ring got folded over.... soon as piston cleared the ring compressor and wouldn't move I went "ohhh $#!t..." took it back and had it re evaluated at machine shop, they honed it out and said "run it".... but I'm afraid to... that was 10 years ago and that bare block is still sitting unused.... gonna get it bored and buy matching pistons to the new bore when it gets used.... 0.007" bore to piston clearance on that one hole seems too much (I don't have forged pistons and this engine isn't being built to crazy enough power levels to need them)