.270 is one of those 'Karma' rounds where you can do things with them you aren't supposed to be able to do.
For deer hunting, it's just AWESOME!
Redly accurate out to 200 or 300 yards with soda straw thin barrels,
Shoots flat as can be,
And the bullet carries enough energy to do the job when it gets there!
Just a GREAT all around white tail gun!
Remember, the .270 is a necked down .30-06 round...
Long action rifles are inherently less accurate since the longer cutaway action twists more when firing.
I'm not sure it will matter with a light weight barrel hunting rifle in 'Mountain Hunting Trim'...
But that is the only draw back I can think of unless you decide to hunt outside of the country... Then acquiring ammo can be a pain outside of the US.
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Don't rule out shorter actions, like the 7mm-08 Remington.
About the same deal, but with a shorter action, so the action is inherently more accurate...
Again, with thin barrel and light weight stock, it's probably not an issue with a 'Mountain Hunting' rifle.
7mm-08 is a necked down .308 Winchester cartridge case, and just like it's 'Big Brother' (.270) it's hyper accurate hunting round that will SERIOUSLY get the job done!
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Then there are the old .30 caliber standby rifles,
The .30-06 and .308 Winchester.
They have virtually IDENTICAL muzzle velocities, and bullet weights/trajectories, but the argument will continue to rage for many years past this one which one is 'BEST' for hunting...
(and I'm not going there!)
I have hunted outside the country, and both .308 and .30-06 ammo is available most places if that will ever be an issue.
One thing about any caliber the military used or uses,
there is TONS of load data out there,
Everybody makes something for them, and most of it works,
And you can even buy optics with ACCURATE bullet drop scale etched right into it.
Resale value is always good on military calibers, plus you get to waste 'Cheap Surplus' ammo for plinking and target practice.
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Some people like .243 rifles for White Tail deer, but I'm not one of them.
I don't like a .243 for much of anything other than coyotes, and I hunt more varmints than just coys...
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No matter what anyone says, .223 Remington is just too light for robust white tail deer.
I'm sure I'm going to take some heat on this opinion from people that HAVE dropped a white tail with a .223,
BUT,
You *CAN* make loads that will RELIABLY & HUMANLY put a white tail down, but they don't usually have them at Wally-World and you often have to modify the rifle to shoot 'Long & Heavy' hand loads...
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Here is a bit of information that might help you save some BIG bucks...
OPTICS!
There is no substitute for Leupold.
If you take a look around at a bunch of PROFESSIONAL GUIDES & HUNTERS, you will see 3 Leupolds for every other type of optic you see,
Or have a look around at any given rifle match,
You will see about 1/2 using Leupold, and the other half using a mix of this and that.
That should tell you something about Leupold.
Burris is about 2/3 the optic Leupold is, but Burris is accurate and rugged... And about 1/2 the price.
Stick with AMERICAN OPTICS...
I don't shoot in 'Meters' so I don't want an optic that is ranged in 'Meters'... I need YARDS!
Stick with about a FIXED 6X or so...
It will save you money, give you a GREAT field of view,
and when hunting, you don't have time for all the gimmicks and gadgets on optics now...
Just 'Point Blank Zero' your 4x or 6x optic at 200 yards...
At 200 yards, you can aim dead on from 50 to 300 yards without hold over or under...
If you zero at 200 yards,
The bullet will be about 1" high at 100 yards,
The bullet will be Dead on at 200 yards,
The bullet will be about 2" low at 300 yards.
Still PLENTY ACCURATE to blow the heart out of a white tail without having to try and figure bullet drop and all that jazz...
And a reasonably LOW (4X or 6X) power optic will give you a much LARGER field of view so you can see what's going on downrange and behind the deer,
And still provide you with PLENTY of magnification for great shots at your self professed 200 to 300 yards!
(saves you a TON of money on high powered optics too!)
I try and stay away from 'Click' type optics adjustments in hunting optics...
I like the low turret (doesn't snag on everything in the bush)
And I like the friction type adjusters since sometimes you just don't want a full 1/4 or 1/3 MOA at 200 yards.
Friction adjusters allow you to 'FINE TUNE' the optics better than 'Click' type in my opinion...
(I'm sure the 'Fan Boys' are going to make a big fuss about that statement too, but I'm a hunter with 40+ years experience, and that is what works best for me and most other long time hunters I know)
I have taken about every kind of large north American game you can think of, Moose, Elk, Mule Deer, White Tail, ect.
And you OFTEN wind up with only a momentary shot situation where you walk up on or jump up the game.
This is where a reasonably low powered, fixed power optic really shines!
You know that whitetail will hesitate before it throws up the flag and bolts, and if you have a hunting optic with more switches and knobs than the space shuttle...
The deer is going to be laughing at you all afternoon!
If you have an optic you can make for a fast, or even MOVING shot, you take Venison home!
Just some things to think about...
I suggested it first... 
