"Hacked seventeen-year-olds to death with shovels" in Korea?

I was just watching Gran Torino and Clint Eastwood’s character says, “I hacked seventeen-year-olds to death with shovels,” referring to his time in the Korean war. What the hell is he talking about? Why on earth would American troops be hacking anyone to death with shovels in the Korean war?

Entrenching tool can be used in hand-to-hand combat.

In hand to hand combat you’d use whatever you could. I just saw that movie and when he said that, I envisoned a position being overrun and intense close quarters free for all.

And ‘seventeen-year-olds’ refers to the comments by many veterans that soldiers from the North or from China were often very young conscripts – ages 16, 17, 18 were said to be common. Not sure if this is actually true – Americans aren’t the best at estimating the age of asians, especially in the middle of hand-to-hand combat.