1" vs 30mm vs 34mm

[GW]

What are the advantages or disadvantages of the smaller or larger riflescope tube diameters?

[unusedusername]

Larger means more light and more weight. Smaller means less light and less weight.

[d33pt]

You can also dial more elevation with a larger tube.

[HK Dave]

The only tangible advantage is more adjustment travel. Larger tubes do not allow for more light.

Some will say larger tubes also allow easier design for high resolution but an engineer at Vortex says that is bunk.

[Carcassonne]

Besides more adjustment, a larger tube may be more rigid. Larger tubes have more surface area and can act as a larger heat-sink/radiator than smaller tubes. I do not know if those things will make a difference to most people.

[OpticsPlanet]

Larger tube diameters do not allow/conduct more light.

Larger tube diameters provide more internal space for things like illumination and turret travel/adjustment.

-Matt S.

[Calico1404]

Larger tube diameters do not allow/conduct more light.

Larger tube diameters provide more internal space for things like illumination and turret travel/adjustment.

-Matt S.

Excellent when a response comes from a professional.

[Calico1404]

The only tangible advantage is more adjustment travel. Larger tubes do not allow for more light.

Some will say larger tubes also allow easier design for high resolution but an engineer at Vortex says that is bunk.

Funny when you actually speak to some of the guys in the business what you learn.....

[snacktime]

Buy a 1" scope, most common , always on sale.
Buy a 30mm Scope only if you want 1-4 or 1-6 power.
If you asked about 34mm you don't need one.

[Horrendo Revolver]

Larger tube diameters do not allow/conduct more light.

Larger tube diameters provide more internal space for things like illumination and turret travel/adjustment.

-Matt S.

This. The idea that larger diameter tubes allow more light transmission is a myth that refuses to die.

[Divernhunter]

I might add that often the larger tubes require taller rings and that often hurts you for a proper cheek weld.
This can hurt accuracy and can take longer to position your head to see thru the scope which can cost you a shot at an animal if it was a quick shot or nothing. It happened to me once. Now all hunting scopes are 1" and 40'ish dia lens because the larger 50mm and up also cause you to usually need taller rings.
I understand some rifles(like AR's) are different and not as effected.