Bedbug, before criticizing someone take the time to read their post. The OP says at the end of his post " ASSUMING YOU ARE USING THE CORRECT BARRELS AND MAG."
To the OP, yes there are conversions that will allow you to shoot 9mm and 357 sig (2 different conversions of course) out of a 40 s&w. Usually the same mags will work for the 357 sig and the 40 just a different barrel and spring. All 3 (barrel, recoil spring and mag) will need to be replaced to be able to change over to a 9mm. You cannot convert a 40 to fire a 10mm, at least none that I know of.
To shoot all 4 rounds out of a 10mm doesn't seem to far fetched with a proper conversion but I don't know about that.