30mm vs 1 inch tube for scope

[Bart B.]

If a scope's sighted in from a low position on a rifle, then raised 1/4 inch, bullets will strike at all ranges only 1/4 inch lower from point of aim if the elevation adjustment is set to previous zeros for all points down range.

Some right handed shooters who are left eye dominant mount their iron and scope sights a couple inches left of vertical on the rifle. They'll use about 2 MOA more left correction to get a 100 yard zero, but only 1/5 MOA correction left at 1000 yards on the windage knob. That's what's needed move bullet impact 2 inches left at both ranges

 

[Tract Optics]

You might want to run that theory through a ballistic calculator a couple times.

Computer programs don't always work for real world situations...

Had a customer with more steel in his neck than he would have liked. Was shooting I believe a .22 cal (can't remember exactly anymore) and literally had to mount the optic in the neighborhood of 3+ inches above rail. He simply couldn't move his neck down. Was shooting a 1" Tasco, cant remember model, but after mounted and had the zero he desired ...he didn't have the the ability to dial to the distances he wanted. I believe he was wanting to shoot and dial from a range of 10 yards to 100.

Some lesser cost 1" scopes even at mid range magnification have very small adjustment ranges...and after mounting and corrections to hit your zero....are very limited in their left over ranges....especially in odd circumstances. Now, in his same pricing ballpark were some 30mm Leapers scopes (yes, Leapers) that would have increased that travel greatly, which would have allowed for this ability. In this case, the extreme angle difference and height of the optic to bore with limited internal travel played a role in choosing the appropriate optic.

Most people will never know this...but when you outfit thousands of people over years and years....you see a lot. Also, never a better feeling than helping someone get back out there.

 

[Haxby]

The combination of a 3" sight height and a 10 yard zero had not occurred to me.

 

[cdb1]

This ALL DAY LONG!!!

+1.

Another dirty little secret is many scopes with 30mm tubes have 1" tube internals in them so you don't gain any added adjustment. A 30mm tube is stronger, but that is about all you are gaining.

 

[Bart B.]

cdb1,

How many scopes, and what makes/models, of each tube diameter have you taken apart to verify internals are the same? If they really were, the windage and elevation adjustment screws wouldn't be long enough on those 30mm versions to get equal movement in all directions from mechanical/optical zero.

And if both tube diameters have the same wall thickness, the 1 inch ones will be stiffer and stronger than the 30mm ones.

 

[sage5907]

I think there is more misconception in the discussion of the difference between the 1 inch and 30 mm tubes than on anything that is discussed on thehighroad. When the original poster reads the postings on this thread he won't know any more than when he made the original posting. The only way for anyone to form an opinion is to try both size tubes and then make a decision for themselves. I have both sizes and have used them through many hunting seasons. There doesn't seem to be any difference in accuracy when comparing the two types. If you want a straight 4 power scope then the 1 inch tube is the way to go because the field of view, brightness and clarity is excellent. On powers greater than 4 power the 30 MM tube works better for me. My favorite hunting scope is a 3 to 9 power variable with a 30 mm tube that weighs about 13 ounces. The problem with 30 mm tubes is that most manufacturers are adding a side focus which increases the weight about 5 ounces and an 18 ounce scope is too heavy for a hunting rifle. I have two scopes with side focus and I very seldom ever use the feature.

 

[cdb1]

My only qualification is having sold firearms and scopes for one of the four largest Cabela's. I was the scope person for that store and as such had frequent contact with the dealer reps, visited several scope companies facilities on more than one location and mounted many scopes a week. In addition I've taken a apart a few busted scopes just to see what made them tick. Not many but a few.

30mm tubes tend to be stronger because the walls are thicker.

 

[dwjwin50]

One of the greatest benefits of the 30mm tube are several more minutes of additional time deer hunting at dawn and dusk.

Because a larger aperture allows more light transmission, just like a larger objective lens. Also, in the metric world it's easier to say 30mm than 25.4mm. d;-)

 

[Haxby]

Because a larger aperture allows more light transmission

You think exit pupil has something to do with scope tube size?

 

[HankB]

Because a larger aperture allows more light transmission, just like a larger objective lens.

Nope - unless the lens design is defective and introduces vignetting, all else being equal a 50mm objective will admit the same amount of light into a 1" tube 'scope as into a 30mm tube 'scope. And you'll get the SAME exit pupil diameter at a given magnification.

 

[MIL-DOT]

I agree with all the posts pointing out why the 30mm tube is NOT significantly advantageous.
Long story,short, after dealing with both, I'll stick with 1" scopes from now on.

 

[chicharrones]

What about lit reticle scopes? I seem to notice many more lit reticle scopes built with 30mm tubes than 1 inch tubes.

Also, I still wonder about why 30mm tube scopes can seem to have a larger variable magnification range than a 1 inch scope?

 

[Haxby]

30mm tube does give a little more room to run wires to reticles.
There are 5x zoom (3-15 and 4-20) 1" scopes. The 6x zoom and more all seem to have bigger tubes. I don't know if there's a solid reason for that, or if it's mostly marketing. As prices go up, companies tend to add groups of features to the same models.