RE: Light Weight Rifle
I think the VX-III 2.5x8 is a good choice - that's what I'm putting on my Browning Titanium (7mm WSM) I have on order. Seems about the lightest variable that maintains 3.5" eye relief.
The VX-III 3 x 9 40mm, VX-II 3 x 9 and a couple of Swarovski's are in the 13oz or less range too.