The actual magnification specs given for this scope in the 2012 Leupold catalog are 1.4X and 4X.
I was looking up the same thing as you were posting. A quick visit to the Loopy website, in the specs of the various scopes, shows this:
VX-2 1-4x20mm........Actual Magnification........4.0 (1.4)
VX-2 2-7x33mm........Actual Magnification........6.7 (2.4)
VX-2 3-9x40mm........Actual Magnification........8.8 (3.2)
VX-2 4-12x40mm.......Actual Magnification........11.8 (4.3)
All of these are closer to a factor of 2.75X than they are to 3X.
So the 1-4x, according to Loopy, is exactly 4X. Even if it's not exactly 4x, if anyone eyes can tell the difference between 4.0 and something fractionally less, as in 3.9, his eyes are better than mine.
Steve.