dogbone
Ultimate Member
It's not the hammer you're worried about, but rather the spot in the lower where the hammer will fall. It's thin there and can break through. Okay, that's "supposedly" since I've never seen one. Sticking your finger in front of the hammer is cheap insurance in case the rumor is correct.
Sticking the rolled up finger of a leather glove in front of the hammer works just as well and is less painful.