 CONT: When Rambo jumps off the chopper to rescue the POWs in the  NVA camp, he pulls off the mounted machine gun which has about 30  bullets hanging on the chain. However, he fires more than 30 bullets  in the scene. Later when Rambo jumps off the chopper at the base, he  pulls off the gun from its mount again with only 30 bullets left.  When he fires at the technology though, he uses at least a hundred.