I know what you mean.
I replaced the 1-piece firing pin in my FAL as they have similar pin breakage issues. After swapping them I had too much FP protrusion with "identically interchangeable" parts! I ended up using a FP protrusion gauge & re-grinding the FP front half's tip, but only after a lot of checking to find where EXACTLY the discrepancy was. Luckily I discovered the problem before there was a problem.
Allan Quatermain: “Automatic rifles. Who in God's name has automatic rifles”?
Elderly Hunter: “That's dashed unsporting. Probably Belgium.”