Question

Why was the M60 called the 'pig' during the Vietnam war?

Answer 1

Manufactured by Saco Defense Inc., this 7.62 x 51 mm weapon weighs 19 lbs, 4 lbs less than the M60 (called "The Pig" because of its 23 lbs weight), ...!

Answer 2

Called " The PIG " because it was trouble prone( likely to jam etc) and its weight was heavy. Hence, take the "P" in prone and the "IG" in weight and you got the "PIG". by military history encyclopdia.