So how much 9mm ammo does the army have anyway? It isn't personally important to me but it is an interesting question. Also, I have never been part of any military equipment selection or acquisition program, unlike (apparently) several others here. However, my late father-in-law, who was an aeronautical engineer, was. He worked at what was at the time, DARCOM, in connection with rotary wing aircraft. He had more than a little to do with the development of some helicopters. But once my son happened to ask what a certain model cost, and he had no idea. But I don't think there was any politics involved. But I also realize that helicopters are not as important as handguns.
Another think that does happen, though, is there are both competing demands for such money as there is (there's never enough, of course) and moreover, there are competing concepts involved, which is nothing new. That goes back beyond living memory and it won't change. What I mean by the last comment is that, for example, the army thinks it needs a certain kind of airplane and the air force thinks the army shouldn't have any airplanes. It may turn out that neither side is even seeing the problem the right way, so that no matter which side wins, they went with the wrong solution. That's only a general picture of the story but you get the idea.