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>> “Soldier hammered pin in with .50 cal round...” <<
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Using the primer end as the hammer, I trust?
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Possibly, using it as a hammer to drive in the retaining pins would make something almost resembling sense. Or maybe, using the round as a drift punch to try to drive the crosspins out. I could see that happening after using dummy rounds that way in a training environment, then being sent off to the land of rusted equipment and Live Ammo, AKA the real world.
In any event: don't do it. And avoid those who do if you can, and if you can't, don't turn your back on them.