40 mm vs. 50 mm scope.

[nwihunter]

I posted this thread in the firearms section instead of the optics figuring it might get more views. I admit I’m not very knowledgeable about rifles and scopes but am wondering what the advantages or disadvantages are to having a 50mm vs a 40 mm lens scope? I currently have a Leupold vx-3 HD 4.5 -14 x 40 on my rifle and is definitely the only quality scope that I’ve ever owned. I recently sighted in a rifle for a friend of mine that had a lower end Leupold scope but with a 50 mm lens and found that I liked it more than the 40mm that’s on my rifle so it’s got me thinking about getting a new scope. Any down side to the larger lens?

 

[Nick87]

Being higher of the center of your bore. Probably not enough to worry about though.

 

[Salmonchaser]

If you have younger eyes you may be able to take advantage of increased light transmission however if you are pushing middle age your eyes are becoming more limited in how much light they can receive so the light transmission advantage is lost. I’m not an eye doc but my eye doc is a big time shooter, competes all over the country and says the light transmission sales pitch is a gimmick. Yes more comes through but older eyes just can’t take advantage.
Im interested in what aspect of your friends scope you liked, was it a 4.5x14 also?