There is a Glock 30S model which is basically a Glock 30 frame with a Glock 36 upper (barrel & slide assembly). It is NOT the same pistol as a standard Glock 30.
Obviously the 36 barrel will work in a Glock 30S, but it would surprise me to find that the 36 barrel will work in a standard Glock 30. Glock doesn't claim that the parts will interchange and the barrel Lone Wolf sells (see the link in Scrounger's post above) states that it is ONLY for use in the 36 and 30S.