One of my classmates is serving at the war front in Eastern Ukraine since Summer this year. When soldiers get there, they start paying special attention to the armor that they receive. It can make a difference between life or death.
My classmate got a really old helmet from soviet-times made in 1952. It protects only from stones.When soldiers tested these helmets they were not surprised that AK-47 bullet breaks through both sides (they shot from the descent distance).
After making some research we found that we can buy some used US army advanced combat helmets of a good quality. You can find many of those on eBay for $150-$200. And they can legally be shipped to Ukraine. That’s what we did. My classmate’s head is much safer now!