The Rambo movies have always been a great source of situational comedy if you have had any military training. Rambo II has quite a lot of these moments; during grande finale there are two scenes that come to mind. During one battle, there is something like a squad (30 men) shooting Rambo from the other side of the river, most of them lying down. Then on the other side there is Rambo with his trusty old M60, standing and shooting the Vietkong. And they are all hip shots! He single-handedly destroys the said Vietkong squad. Hilarious! We had to rewind and watch it again to see if all of us just thought we saw it.
The second scene is when the POWs and Rambo are sitting in the (was it shot down, I don't remember?) chopper and the other chopper is closing in for a kill. Rambo pulls the light rocket propelled grenade launcher and shoots down the chopper. What's wrong with this scene? Well that type of RPG has a quite strong bang when it is launched, thus the shockwave will disable the people in the chopper as the shockwave cannot expand in every direction. And because the launcher itself is a hollow tube, the hot gasses are ejected backwards, frying the veteran(s) behind. Way to go Rambo.
The Browning scene in Rambo IV trailer is funny because it is idiotic, and there are at least two reasons for this but I wont elaborate it further to spoil someone's movie experience. But anyways I'll probably go see the movie in the cinema to get good laughs for the uninteded situational comedy. As the rest of us here, I suppose. And the more I watch the trailer the more I see these things. Oh yes, that's the good stuff. [As people will not get this reference, check out William Shatner singing Rocketman and then Family Guy Rocketman scene.]