G17 Caliber change???

[IIIBoomerIII]

A friend of my tells me that in order to change from
a G17 9mm to a .40SW or a .357sig that all I had to
do was buy a barrel and a magazine. Is that really all
there is to it??????:dunno:

[JR]

Your friend is wrong.
You can convert a 40 or 357 to fire 9mm ammunition with a simple conversion barrel.
You can not convert a 9 into a 40 or 357 with a complete top end.