So I love the amount of weapons that fook2 adds but most of them use incorrect calibers IE the ak 47 uses 5.45 instead of 7.62. So I really want to overhaul all of the ammo and make them as accurate as possible but need instructions on how to do so.

So if anyone can help I would very much appreciate this!

Edit: I want to use excalibr for weapons

If you haven't seen it already you might be interested in this mod: http://fallout3.nexusmods.com/mods/11726. I haven't used it but from the description it sounds like it does something pretty similar to what you're planning to do.