Some thoughts and observations, based on having setup up a healthy number of "mountain" rigs for customers, using a variety of lightweight mountain-style rifles (Tikka T3 Lites, Sako Finnlights, Christiensen Arms, Browning Mountain TI, Kimber Mountain Ascent, RMR, Forbes Model 20, HS Precision PHL...).
Huskemaw, Leupold and Vortex do not enter into these discussions as I cannot speak from personal sales experience on these brands - however all three, certainly Huskemaw and Leupold have asserted themselves as excellent candidates for this type of setup.
A "long-range mountain" rifle has few requirements in mind:
1 - lower overall weight,
2 - balance,
3 - durability,
4 - adequate magnification range for ethical "longer" shots (at least 14 power at the high end),
5 - some sort of ballistic reticle or turret (either mil/moa click-dilineated, or preferrably in yards/meters).
Accordingly, and at the risk of ruffling some feathers, certain brands/makes, models, and inherent specifications make some rifle scopes less desirable for a "mountain" setup (this is all observational, not authoritative, so feel free to disagree).
Zeiss Classic Conquest line: with the discontinuation of the Rapid-Z reticles in this line and without the availability of a ballistic turret, the Classic Conquests are no longer candidates.
Zeiss Victory HT line: with a maximum mag of 12x in the 56mm objective model, this line falls short in the magnification department.
Zeiss Diavari line: the 4-16x50mm and 6-24x56mm models could be considered, however they run in the 725 - 800 gram range, making them a tad heavy.
Sightron: excellent value for money scopes, however they admittedly lack the durability required for hunting in an alpine environment.
Nightforce: while outstanding, exceedingly durable, feature-rich, long-range scopes, an NXS 5.5-22x56 tips the scales at close to 900 grams, making it both heavy and unbalanced. That being said, a personal friend packed his 338 Edge sporting an NXS 5.5-22x56mm into the mountains this year and bagged a sheep, so if you don't mind lugging that sort of rig around the mountains, it can serve you well.
The March Hunting 2.5-25x42mm:
Cost: $2,450
Features: 610 grams, 30mm tube, 42mm objective for low profile and balance, 100 MoA of adjustment, ED glass, widest mag range of any scope available
Cons: MoA based turret (vs. range dilineated ballistic style turret), limited availability in Canada, warranty, weight
Swarovski Z5 3.5-18x44mm with Ballistic Turret (or BRH/BRX reticle):
Cost: $1,599
Features: 451 grams, 1-inch tube, 44mm objective for low profile and balance, very useable mag range, outstanding warranty, flexible and user friendly ballistic turret system
Cons: only 36 MoA of adjustment
Swarovski Z5 5-25x52mm with Ballistic Turret (or BRH/BRX reticle):
Price: $1,739
Features: 495 grams, 1-inch tube, wide mag range, outstanding warranty, flexible and user friendly ballistic turret system
Cons: only 25 moa of adjustment, 52mm objective is largish for a mountain-style setup, 5x minimum mag is "too high" for some
Swarovski Z6 5-30x50mm with Ballistic Turret (or BRH/BRX reticle):
Cost: $2,699
Features: 600 grams, 30mm tube, highest magnification of any scope in its weight/quality class, outstanding warranty, flexible and user friendly ballistic turret system, some of the best HD glass available in any scope
Cons: only 25 moa of adjustment, 50mm objective is getting largish for a moutain-style setup, 5x minimum mag is "too high" for some, cost
Leica ER 3.5-14x42mm with IBS or Ballistic Reticle and Target Turret:
Cost: $1,599
Features: 470 grams, 30mm, tube, 42mm objective for low profile and balance, 50 moa of adjustment, IBS/ballistic reticle software is excellent, dovetails well with CRF-1600B or Geovid HD-B ballistic output, excellent optics
Cons: mag range is lacking, the Leica ER scopes are a bit of a dark horse at this point and potential buyers are uncertain
Zeiss HD5 3-15x42mm with Rapid-Z Reticle:
Cost: $1,099
Features: 521 grams, 1-inch tube, 42mm objective for low profile and balance, Rapid-Z reticle system is outstanding, reasonably priced, Conquest line is durable, reliable and well-proven
Cons: on the heavier side, Zeiss does not have an inherent ballistic reticle system (turrets available through Kenton Industries in the US)
Zeiss HD5 5-25x50mm with Rapid-Z Reticle:
Cost: $1,249
Features: 754 grams, 1-inch tube, Rapid-Z reticle system is outstanding, reasonably priced, Conquest line is durable, reliable and well-proven, wide mag range
Cons: 50mm objective is getting largish for a mountain setup, 5x minimum mag is "too high" for some, combination of weight and objective size on a lightweight "mountain" rifle will result in an unbalanced setup, Zeiss does not have an inherent ballistic reticle system (turrets available through Kenton Industries in the US).
Ballistic Turret vs. Ballistic Reticle:
While the choice between these can be a matter of preference, there is a key differential between these two styles of ranging that must be considered: with a second-focal plane scope, the hold-over values of a ballistic reticle (Swaro BRH/BRX, Zeiss Rapid-Z, Leica IBS/Ballistic Reticle, Nightforce Velocity, etc...) vary with the magnification setting. In other words, when a ballistic reticle is setup for specific caliber/load/environmental data, the corresponding range for each reticle subtension will change depending on what magnification the scope is set to. Thus, using the Rapid-Z system for example, given the particulars of the inputs, for the "5" subtension line to equal 500 yards, the scope MUST be set at a specific magnification, or the "5" will not equal 500 yards.
Sometimes, the "optimal" zoom setting (as dictated by the ballistic software) is vaguish and interpolated (i.e. 13.7x) making it difficult to be precise that the scope is in fact at the correct zoom setting. Most modern software solutions allow the user to specify a magnification they would like to operate at (i.e. at 10x power), affording some flexibility, however the output might be difficult to memorize and actualize in the field, especially during a stressful situation (i.e. at 10x, the Rapid-Z #2 line = 176 yards, #3 line = 268 yards, #4 line = 353 yards, etc... rather than the lines falling on even, 50 or 100 yard increments).
For some systems (i.e. NF Velocity) the configuration is simplified, as the scope must be set at maximum magnification for the range values to fall into place - making the "setting" of the scope relatively easy. However using maximum magnification when hunting carries with it a much different set of risks than when shooting paper.
Given these functional realities, the risks/limitations of a ballistic reticle should be considered. First, for the reticle to work, the user must always remember to place the scope at the proper magnification setting before shooting. Second, there are certain situations when the "proper" magnification setting could prove disadvantageous. The primary risk is that when the magnification must be set very high for the reticle subtensions to work as desired, the scope could be zoomed-in more than the user would like when considering target reaquisition for follow-up shots. In other words, you are zoomed-in very close, and after the realities of pulling the trigger (recoil, muzzle-rise, the target moving) you become "lost in the scope" and cannot find your target again without a) "dismounting" your eye from the scope to find the target, and/or b) powering the scope down to a lower magnification for a wider field of view.
With a ballistic turret that utilizes the central point of the crosshair as the POI, the range function works regardless of the magnification setting. Of course, the user must remember to turn the turret to the correct value/setting prior to shooting.
Given the allowance for variable magnification, it can be argued that a yard/meter dilineated ballistic turret affords the user more ease of use and flexibility, while reducing the risks of becoming "lost in the scope" - merely an opinion and certainly open to debate.
Recommendation:
Swarovski Z5 3.5-18x44mm with Ballistic Turret - light-weight, balanced, outstanding optics, optimally sized objective, durable construction, best warranty in the business, excellent magnification range, user configurable ballistic turret (custom turret optional), and reasonably priced.
When paired with an optic/rangefinder that provides Equivalent Horizontal Distance (i.e. Swarovski EL-Range, Leica CRF-1600B, Leica Geovid HD-B...), it makes for a straight-forward and very effective combination, particularly in the mountains.