Uncommon Valor (1983) on Netflix

A Marine Colonel who was dismissed because he wouldn't give up on the notion that his son who's an MIA in Vietnam is still alive. Nearly 10 years after his son went missing, he obtains evidence of where he might be--a P.O.W. camp. So with financial backing from the father of another P.O.W. he recruits some men who served with his son. With photos he obtained, he makes a replica of the camp and they work out a rescue operation. But the government tries to stop them. And when they are about to go, their weapons are confiscated. So they have to find other weapons.