I am tantalized by ammo boxes on the back of Army Truck. But I can't seem to jump into the back of the trucks. There are no steps and no way to climb. I also tried to get up on the running boards. Is it possible to get on the back of the trucks?

There are some trucks that are simply impossible to get into. Why they did it that way is beyond me, it drives me up a wall when I come across one. Most of them though, if you look, will have some way to make it up there with a bit of work. Like a stack of boxes you can climb on to.

When you drop single 5 mm rounds, it creates a huge ammo box. Before I actually own a mini-gun in-game, I carry a handful of these around for these situations. I use them to step up.

Sweet! I'm going to keep that in mind.

I don't think I've found a single truck I couldn't jump into, without ever dropping or moving stuff.

You can just jump in the right direction. Usually there is a small step to help you up. Then I find that sometimes I need to jump at an angle to the back of the truck rather than just jump straight in. That way you can move (run) a very short distance and jump. It might take several tries but it works for me. Also sometimes you can take a running jump to get in the back, as I recall.

make sure you're not in sneak mode.Its harder to jump that way.

You're talking about the Army trucks in front of the Army Dept that the MIRV is in, aren't you?

Those were the hardest (No doubt) trucks you can climb in the game. But, I forgot how, but I managed to jump on the fence and jump inside the trucks. Try finding a way to do that.

Sometimes I have to move barrels over next to the truck then jump up on the barrel from which I can jump into the truck...

Not there yet, but I will give the suggestions listed a try!

I just tried this with a very small character & it worked great!

Thanks for the tip