http://www.nexusmods.com/newvegas/mods/55243/?tab=1&navtag=http%3A%2F%2Fwww.nexusmods.com%2Fnewvegas%2Fajax%2Fmoddescription%2F%3Fid%3D55243%26preview%3D&pUp=1
You could try this mod, I have never tried it but it appears to have many weapons from ww2.