The Glock 30 is larger than the Glock 26 or 27, but if I recall correctly, a little smaller than the 23 or 19.
Here is a picture of a 19 and 30 together. The 30 looks just a little smaller in the grip and frame length.
Last edited by 5.56RifleGuy; October 4, 2012 at 12:32 PM.
Reason: Found a link with a picture.