How many of you guys wore a bent nail in your utility cover (fatigue hat) for sight adjustment on the OLD M-16 before dial-in sights? They were actually issued on the firing line in the Marines in the 1970's. My guess is this will apply only to Marines and Navy men like myself who shot with Marines, as the Army just did a 25 yd. BZO; whereas Marines put dope on for 200, 300, and 500 yard stages.
You could use a bullet tip but even in tho old days the Corps did not want loose rounds floating around for Private Pyle to take into the head and confront the gunny with.