Which of these scopes for a 338 RUM?

[midgetorama32]

A friend of mine is selling me his 338 RUM Sendero and is going to stick one of his Leupolds on it as well. I was wondering which would work better for long range shooting/hunting.

1. VX-II, 4-12x40 AO, M1 knobs, duplex reticle

2. VX-II, 4-12x50, M1 knobs, duplex reticle

The 50mm objective seems clearer to me. Is there any disadvantage to not having the adjustable objective?

Thanks for any thoughts.

 

[Weidah]

AO will help you eliminate parallax.

An example of parallax can be seen here



If you pay attention to when he's moving his head left and right you can see the crosshairs move off the center of the target. With AO you can eliminate it and make better groups.

 

[davewilson]

[QUOTEWeidah;
If you pay attention to when he's moving his head left and right you can see the crosshairs move off the center of the target. With AO you can eliminate it and make better groups.

in theory this is true. the problem with these Leupold scopes is the AO adjustment is notorious for changing the point of impact as it is rotated. i use a non parallax adjustable scope for my long range rigs and they work just fine. the way you eliminate parallax is to line up your eye so there is a slight black ring around the edge of the field of view. just like in that video. get the black ring concentric in the scope every time and you've eliminated parallax. a non AO scope has less lens, is tougher, and is always in focus no matter what the range. for a hunting gun, i think a non parallax scope is better.