Arthur Haecker Posted 5 months ago Malcolm Gladwell: The unheard story of David and Goliath In comparing the force of the sling stone to a modern handgun, Mr. Gladwell mentions a "45mm" handgun. I think he might have ment 45 cal., a reletivly slow moving but heavy slug. A 45 MM shell is the sise of a large ainti-aircraft shell. That shell is about 2" in diameter and about 1 ft. over all. Damn good talk though.