1" VS. 30mm

[Chazman321]

With 30mm scope, you have a greater range of adjustment in elevation and windage, which is better for long range shooting. Also, it is easier to align your eye behind the scope.

^^^This. I was 3 minutes late... lol


-Chaz

[EODguy]

With 30mm scope, you have a greater range of adjustment in elevation and windage, which is better for long range shooting. Also, it is easier to align your eye behind the scope.

I would have never thought of that, good point.

[PaBimmerGuy]

Because IMO 30mm isn't that much bigger then 1". In reality it is bigger but not that much bigger.

area is what is important. 30 mm has an area 40% bigger than 1". 40% is a lot bigger.

quality of optics is important too but all other things being equal bigger is better.

[Tomcat088]

Others have touched on it and given the correct answer. The 30mm main body tube will have more room for adjustment in terms of elevation and windage. The point that people have brought up related to the surface area isn't one of the main reasons. While the initial calculations about area are true, that doesn't mean it makes much of a difference. If the 1" area is sufficient, then having more probably wouldn't have a huge impact. Things just get complicated when you consider things like that because you have to start considering other factors. Most of the time, the rings don't make good flush contact with the scope body. There's a reason that quality rings are lapped, or don't need to be lapped and cheap rings need to be. It's because they don't make good flush contact with the scope body. So it really just depends on lots of factors. If some good 1" rings made more flush and better contact than some cheap 30mm rings, it's very possible that they have more contact surface area than the unlapped and cheap 30mm rings. You'd also have to start consider things like coefficient of friction, since there can be differences between different metals, and finishes. You'd also have to make the calculation using simliar torque settings, all under the assumption that the body tube could tolerate those torque settings. So really guys, there's just not a huge benefit in terms of friction and surface area between 1" and 30mm rings. Yes it exists, but it's not the real reason.

Someone mentioned that the 30mm body tube will make the optics "brighter", and this is a myth. Objective size and lense coatings have a MUCH bigger impact on brightness than the body diameter. Uusually, the light is focused down to a small column as it passes through the main body tube area. This is normally much smaller than even a 1" body tube, so it passes easily through. IF the exit pupil and the lenses made it so that it was able to get closer to the main body tube, it would be a factor. So most of the time, in most scopes, this isn't a factor that effects brightness at all. Quality of glass, coatings, number of lenses, and objective size, will have more of an effect on brightness.

As others have stated, the main reason for a large main body tube is related to the adjustment range. The assemblies that move lenses and the reticle inside of the scope body take up space, obviously, lol. If the assembly has more range to move up/down and left/right, then it allows you to have a larger range to adjust your zero, or use for dialing windage or elevation. You have to keep in mind that the lenses are circular like the tube, so you aren't able to go all the way to the edge. As you get very close to the left or right side of the tube, you won't be able to go all the way to the top or bottom of the tube. The edge of the lenses and erector assembly will hit the area that is in the respect 10:30, 2:30, 4:30, etc. positions. If the tube is a larger diameter, then it gives a bit more room to adjust.

It's really important to remember that this is just a general "rule of thumb". The reason that this is the case is due to manufacturers' differences. Remember that different companies use different styles, types and systems for adjustments. Some systems will take up more space than others, and some parts will have larger pieces than others. The larger the parts inside of the scope, the less room they'll have to travel for adjustment. One should also remember that when you're talking about 1" or 30mm diameter tubes, this is measured by the OUTSIDE of the tube. That's why you can use different 1" or 30mm rings from different manufacturers and still have them fit other scopes. Not all manufacturers use the same "thickness" of main body tube. You can think of it as using a different gauge of metal for the tube, but the outside dimensions end up always at 1", 30mm, etc. What this means is that the inside dimension of the scope will have slightly more or less room to travel depending on the thickness of the tube. It's a trade off like anything else; a thinner tube will give more room to travel, but it will be less rigid. A thicker gauge of main body tube, will not allow quite as much room for travel AND it will be heavier, BUT it will likely be more rigid/durable/stronger. It's always tradeoffs, like anything else.

The moral of the story is that while you can get a "rule of thumb", you can't overgeneralize too much. The important thing is to look at the detailed specs of the rifle scope. Most manufacturers will tell you how many MOA of travel the scope has from optical center. THIS is what you really want to look at, because it's really what is effected most by a larger tube diameter. You may be surprised to see that some scopes with 1" tubes have almost as much travel as 30mm body scopes of some other brand. So check the detailed specs to really get the true answer and break down the differences between manufacturers and their erector system, tube dimensions, etc. If you have the right rings, and the scope is decent, how much travel it has shouldn't be a problem for MOST people's applications. If you are wanting to dial on elevation for shooting at longer ranges, etc, things can get a little tricky. It will depend on your bases, rings, how far off optical center the scope ends up, trajectory of the caliber, and how far you want to shoot. I know this is all a bit complicated and "long winded", but I wanted to give you more information to draw your own conclusions.

[arrrrgh15]

"1inch WIDE rings", not 1inch diameter rings! You cant figure surface area without the WIDTH of the rings. Since the formula uses the radius of the circle (.5 for 1inch, or .59 for 30mm) it is already evident that you are using the correct ring diameter. You keep the WIDTH the same so as to keep the experiment unchanged in comparing the surface area calculations. "But thanks for playing! Tell him what his parting gifts are Johnny!"

where are you finding 1" wide 1" diameter rings?




After reading some of the posts in this thread, I'm glad I switched to 34mm scope body.

[spblademaker]

where are you finding 1" wide 1" diameter rings?




After reading some of the posts in this thread, I'm glad I switched to 34mm scope body.

Weaver & Burris. I'm sure there are others. Kelbly's rings are .9 inches wide. The width dimension was used for comparison purposes only, making the calculations easier but still keeping the surface area percentages equal. Was there a mistake in the calculation?

[arrrrgh15]

Weaver & Burris. I'm sure there are others. Kelbly's rings are .9 inches wide. The width dimension was used for comparison purposes only, making the calculations easier but still keeping the surface area percentages equal. Was there a mistake in the calculation?

If the point was more surface area, why would they bother making 30mm and 34mm tubes and not just make 1" wide rings for 1" tubes.

Clearly the answer was wrong.

So Johnny, what did he win?

[spblademaker]

What are the dimensions on the rings that you use? You stated that you are using a 34mm body. I guess that is to increase your adjustment capability. I also agree with that. So, figuring that greater surface contact means nothing, why do companies like Badger Ord., Barrett and A.R.M.S. have such wide rings available in 34mm? Why isn't everyone just using dual-screw narrow rings?

[arrrrgh15]

What are the dimensions on the rings that you use? You stated that you are using a 34mm body. I guess that is to increase your adjustment capability. I also agree with that. So, figuring that greater surface contact means nothing, why do companies like Badger Ord., Barrett and A.R.M.S. have such wide rings available in 34mm? Why isn't everyone just using dual-screw narrow rings?

i keep pitchen em you keep missen em.

That's no way to tie down a punkin.




I use badger rings but they aren't 1" thick. That's fer sho.

[spblademaker]

i keep pitchen em you keep missen em.

That's no way to tie down a punkin.




I use badger rings but they aren't 1" thick. That's fer sho.

What are there dimensions? Here is some info from the Bager Ord. website regarding their MAX-50 scope rings, which happen to come in 34mm: MAX-50 Scope Rings

The MAX-50 rings are one Inch wide, giving them 60% more holding power than any other ring available.
Utilizing 6 #8-40 Torx® screws to distribute the load providing the maximum amount of holding power while minimizing the chance of damaging the scope. Machined from steel as “Matched Pairs” and serialized. Mil-Std-1913 compatible (Picatinny optic mount) designed for the demanding .50 BMG round.

I didn't say that surface area was the only benefit for the larger tube, just one reason. It looks like me and Badger Ord. are wrong. What was the scope ring brand you're using?