You might try a short variable (1.5-5/6) some of these have large diameter exit pupils that may help a little particularly if the parallax is set to your normal hunting range... it won't matter then if your eye is a little off center line as long as the reticle is on target....your 3-9 set at 3x should have a large exit pupil eg around 9mm (maybe as high as 12+mm) on most which is about as big as they typically get - the 4x,40 should be 10mm. the 1.5 might get as large as 20mm with a 32 mm obj.... I think someone was selling a B&L 1.5-6 that I believe has a 32mm obj which is going to be about as big as you may find in a reasonably priced scope....