Rifle Scopes 1 inch vs. 30mm vs 34mm vs 35mm

[sirhrmechanic]

Had an interesting conversation at the range yesterday about tube diameter and the advantages of bigger tubes.

Conversation came when another shooter wondered why I would order a 30mm USO when I could have had a 35mm tube... my answer: I like my existing mounts and base, they work well; the 30mm I demo'd was superb and I had no issues with it... so wanted same 30mm tube I had before. Done

But got thinking about it and the three advantages of bigger tube seem to be:

Bigger tube equals more potential light transmission.

Bigger tube equals more surface/grip area for rings (perhaps important with heavy-recoiling calibers such as .50 BMG) where you want to hold the scope as rigidly as possible.

Bigger tube equals more room for erector travel and so more elevation/windage adjustment at ultra-long ranges.

From those who know optics... are there any other advantages? Are these valid? Any disadvantages of bigger tube (less room in a top-feeding rifle?)

I can't think of a disadvantage of a bigger tube (except the expense of buying new rings if you don't have a 35mm set)... and am not sure if my list of 'advantages' is correct or complete or even valid. But thought this might initiate an interesting discussion.

Cheers,

Sirhr.

 

[GMR]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

Bet Doc can answer that question he works there.

i could be wrong but I do not think it is as easy as it seems,

 

[shootist2004]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

your 3rd assumption is correct

 

[brand692]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

Tube size has nothing to do with light transmission.

35mm does provide more surface area for mounting.

Bigger tube DEFINITELY equals more room for erector travel-in most circumstances. There is at least one MFG that has a 34mm tube that has the same elevation as a 30mm tube. The difference is that the tube wall is thicker, and therefore the internal diameter is the same. However, it is a pretty good general statement to assume that all else being equal, a scope with a larger tube has more elevation and windage travel as the erector has more room to move one side to the other, or top to bottom.

My only thing against the big tubes is the lack of rings for them. There are just more options with the 30mm. And I don't have a rifle that would demand the extra elevation of a huge tube.

Nonetheless, I have a buddy with a 35mm 3.2-17 TPAL, and it is SWEET. And I have a PH which is 34mm, but it came with the rings.

 

[scotharr]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sirhrmechanic</div><div class="ubbcode-body">
...
But got thinking about it and the three advantages of bigger tube seem to be:

Bigger tube equals more potential light transmission.
Bigger tube equals more surface/grip area for rings ...
Bigger tube equals more room for erector travel ...
...
</div></div>

Of the potential advantages you list above, only the extra elevation/windage has any merit in my eyes. Keeping the law of diminishing returns in mind, I think you get 99.9% of those benefits with a 30mm tube. After that, the disadvantages start to show up:

1. Heavier
2. Sits higher above the rifle pretty much forcing you to get an adjustable cheek piece. This in turn adds more weight.
3. Heavier scope means more stress on your rings. Of course that can be fixed with bigger rings....add some more weight.
4. Far less choices in scopes and rings in the larger sizes.

Did I mention everything is going to be heavier?

If you just cart it in and out of your car and shoot prone, then no biggie. If you hunt, shoot offhand, or do any other activity with much movement, then these scopes are just too darned big and heavy.

PS. I have a Weaver T-36 with a 1" tube and it gets me out to 1000 yards without any problems.

 

[OFIS]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

I got a 34mm USO because:

-I like Badger rings
-I like to live without regrets
-I wanted something different for my money

The only disadvantage I see is that it is undoubtedly heavier. But a M40/M24 taper barrel is not a lightweight build, so the only disadvantage is a mute point (for me)

If it does nothing else but boost your shooting mojo, its worth the $. Its not all facts and numbers ALL the time, enjoy the ride!

 

[shooting4life]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

I like the 34mm tubes because the chicks dig them.

 

[pklin1297]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

I got the 35mm USO because:

1. It gives me more erector travel vs. the 34mm which just has thicker walls and same allowance as 30mm.

2. It gives me a better hold on the scope when I run out of ammo and have to use the USO for hand to hand combat...



I'm kidding on the second one. Can't wait for USO to get it finished and in my hands!!!

 

[sobrbiker883]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

I got the 35mm on my 5-25 because someone with a bitchin' one off USO that happened to be 35mm traded me a Premier for it!!

 

[SilentSoul308]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

I run a Premier Heritage 5-25x with 35mm Badger rings........I'll never go back!

 

[HuDisCo]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

I am no engineer, but I talk to lots of them.

I also understand that a larger tube allows the use of larger lenses in the erector system. This allow for much higher quality when looking at the edges of the FOV.

It has nothing to do with light transmission, but the OP's other points are valid; more mounting surface area, and more room for erector travel.

Hope that helps.

 

[Turk]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SilentSoul308</div><div class="ubbcode-body">I run a Premier Heritage 5-25x with 35mm Badger rings........I'll never go back! </div></div>
You sure about that?

 

[generalzip]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

While there is more surface area on contact with the rings there is also more weight and with weight more stress on the rings during recoil. Does the new system become stronger or weaker? You would have to do calculations/experiments to find out. F=ma. Acceleration would remain near constant and is very high. Adding any weight would create a linear relationship with force. You would have to find out just how much stronger 30mm rings are vs. 34 and 35mm rings. Material selection would play a big part. Steel rings probably being the strongest while adding even more weight.

 

[OFIS]

Re: 1 inch vs. 30mm vs 34mm vs 35mm

The internal allowances of a 30mm were fine by me. My 308 dope is maxed out within the first quarter of the second turn.

I also had it built non-illuminated, so I must be clearly insane.

The most priceless feature of mine is that Im happy every time I see/use it, and it keeps me from wanting anything else.

When you get down to the nitty gritty of light transmission, clarity, erector travel etc. really honestly think about what YOU are using it for. If you want nothing more than the end-all telescopic multi-tool, are you really taking full advantage of having one built for YOU and your application?

I will call myself out on getting off topic of OP, I apologize. but as a reference for the 1% who search, think outside the box. Take full advantage of the words 'purpose built' when considering USO, its a rare opportunity.