Metric vs Imperial scopes

The ring choices are a little more limited for 30mm scopes but in theory they will transmit more light. Plenty of higher end scopes use a 1" tube though, and have excellent optic performance. A couple more things to consider are that the 30mm will likely give you a little more elevation adjustment, and the 30mm may appear to be mounted lower on the rifle because of the increased diameter of the tube.

My long range Leupold with a 30mm tube is bettered (to my eyes) by a 1" Swarovski Z3. Tube diameter in itself is not the deciding factor of performance.
 
I don't think it matters much really. If you use a mildot/mil adjusments and do everything in mils it will seem natural.

If you do the same with mildot/moa adjustment it will seem natural.

I have done it both ways but I do the mildot/moa exclusively on my scoped rifles now so I can switch rifles and keep the math the same.

I do however keep iSnipe on mils for holdover while hunting and JBM on MOA for come-up clicks while target shooting.
 
Practically speaking, there isn't much difference for most purposes. Most of the perception of 30mm tubes being inherently superior comes from the fact that high end European manufacturers like Zeiss, Swarovski, etc. use this size rather than any specific technical reason.

Light transmission is a function of objective lens diameter and glass quality, not tube diameter. A 30mm tube could hypothetically have more adjustment range than a 1" tube, but many have the same "guts" as their 1" counterparts. A 30mm tube of the same material with the same wall thickness will be stiffer than a 1" tube, but this is not the only thing that determines the durability of a scope.

Pick the scope that best fits your requirements and let tube size fall where it may.
 
I should've been more clear, I didn't mean 1" vs 30mm tubes but rather scopes with metric adjustment (1 click = 1cm at 100yards).
 
IM_Lugger said:
I should've been more clear, I didn't mean 1" vs 30mm tubes but rather scopes with metric adjustment (1 click = 1cm at 100yards).
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don't think of MILs / MOA as metric vs imperial as they are not the are angular measurements all of their own.

here is a link to some good reading

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=378812#Post378812
 
caustic said:
Agreed. 1cm at 100m (not yards!) is just another way of stating 1/10 of a mil.
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Agreed. 1cm at 100m (not yards!) is just another way of stating 1/10 of a mil. Degrees/minutes/seconds aren't part of the SI system, but are accepted by international standard for use with SI units. The angular mil is named for the milliradian, but is not exactly equal, due to rounding for convenience (6400 mils to a circle vs. 6283 mrad to a circle).

Regardless of what adjustments units are used, they should be consistent with the graduations of a range-finding reticle, if the scope has one. A mil-dot reticle should be matched with adjustments in mils and an MOA graduated reticle should use MOA adjustments.
 
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tjhaile said:
Agreed. 1cm at 100m (not yards!) is just another way of stating 1/10 of a mil.
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Yep! And most companies have moved away from the 1cm notation because its misleading.

A mil is 1/1000 rise over run. 1 mil is 1 meter rise at 1000 meters distance. It's also 1 yard rise at 1000 yards distance. Or 1" rise at 1000" distance...

0.1 mil is 1/10 of that (1/10000). 1cm is 1/10000 of 100m. At 100 yards, 0.1mil is 0.36"... or 1/10000 of 100 yards (3600")

It is not metric, it just works well with metric measurements because they're base 10. It's a moot point if you're running an FFP scope since you don't ever need to think about how many inches or cm 0.1 mil is at whatever distance.
 
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