I was just watching We Were Soldiers... Why didn't America use bulletproof vests during that battle, or in general during that conflict?
Edit: was the fighting really as gruesome as it was in the movie? Was America really fighting that close to the enemy and losing that many men?
That's because they used flak jackets/vests and those are better for protection against fragments from explosives. Depending on the type of flak vest issued, it could protect from bullets, all depending on the type of firearm used and how far away it was fired from.
Flak vests were preferred because it weighed less than the bulletproof vests of that era.¹
¹ Source and more information if you want to read a bit more