Did soldiers steal enemy weapons?

Specifically asking about Vietnam War but others can apply. I know some enemies weapons had a distinct sound or even bullets. This was evident when people would know who actually killed a specific soldier or civilian. In general, I would imagine they would want to take the weapons for obvious reasons such as more ammunition, but if they heard it being fired wouldn't their own side think it's the enemy just because of the way it sounds? May be a tough question but just seeing if anyone knows. Thanks ahead of time.