The Army Times had a story about some army unit testing current model handguns from many makers in calibers bigger than 9mm to see if it was worth switching. From what I heard they were testing 357 sig, 40 s&w, 45 acp and maybe 45 gap.
They did say something about the pistols have to be non-developmental (existing) designs and that the reason they are testing is get an idea of what good possible replacements might be before starting the process of switching.