Harrier is far more eloquant than I, and he pretty much nailed it. I don't think you could go wrong with ANY of the non-magnum calibre offerings. The three you noted above have been around a LONG time, and there's a good reason for that -- they work! The only thing I would add is that if you're going for the Bavarian Carbine, you should invest in the Sako QD rings/bases. It's worth EVERY penny. You can go back to iron sights any time you wish, without fear of losing zero. There is NOTHING on the market that compares in build quality to the Sako QD set-up, period.
Sako QD rings have been somewhat problematical to locate throughout 2013. We have had many customers seeking these rings for their Sako rifles, but to date our Canadian Sako distributor has been unable to secure more than a handful of these rings for existing back orders. The OptiLock system remains the best option for Sako rifles with regard to on-gun security and in-store availability.
With regard to the age-old question of calibre choices, the following is always a good guideline:
The .308 Win cartridge is, for most shooters, a 300-500 yard calibre. (Yes, I know it can be fired farther, but we're talking about the
average hunter here, not Carlos Hathcock-wannabes!). Capable of taking mid-sized to smaller large-sized game (read: coyote up to elk or moose) at normal hunting ranges, the .308 Win provides a stable, reliable and accurate platform for novice to advance shooters. Current ammunition selection ranges from 125-grain saboted rounds, to 180-grain heavy loadings. Powder and bullet loads available from full-scale production manufacturers provide match-grade precision with bullet selections that range from hollowpoint to soft point to bonded or penetrating-point rounds. Retail pricing on .308 Win ammunition ranges from approximately $18.99 -- $40.00 per box of 20 rounds.
The .270 Win cartridge is developed from the .30-06 Springfield casing, necked down to accept a bullet with a smaller diameter. This allows for a lighter bullet to travel at higher velocities. For most shooters, the .270 Win is capable of reaching out to 500-600 yards with excellent accuracy. While bullet loadings range from 110-grain to 150-grain loadings (with some 160-grain loadings available, but more difficult to locate), this calibre has been used to take medium- to large-sized game from deer to moose, and has been reported with some success on moderate-sized bear. The downfall to the .270 Win cartridge is the tendency for the lighter bullet, travelling at higher velocities, to be more easily deflected off target when shooting into cover or brush, thereby reducing accuracy on that loading. Pricing on .270 Win ammunition ranges from approximately $27.00 - $45.00 per box of 20 rounds.
The .30-06 Springfield round has been in production for over 100 years, and is by far and away the most wide developed cartridge currently available from standard-production manufacturers. With bullet loadings ranging from 55-grain saboted loads to 220-grain soft-points, this calibre has been used to take down quite literally every game animal in North America, from ground hogs to black bear. For the average shooter, the .30-06 is basically a magnum version of the .308 Win, and is capable of match-grade accuracy out to 800-1,000 yards. Ammunition selection is broad, and is readily available through any sporting goods shop which carries ammunition. The downfall to the .30-06 round is the considerable recoil, which is noteworthy in lighter weight firearms. Additionally, due to the size of the casing, the .30-06 and .270 rounds are generally limited to 3 rounds only in any magazine, with one extra round in the firing chamber (though extended magazines are available for some rifle models), while the .308 Win offers a fourth round in the magazine, plus the round in the chamber. Pricing on .30-06 Springfield ammunition ranges from approximately $19.00 - $50.00 per box of 20 rounds.
All in all, you will not go wrong selecting any one of these three calibres. In the end, the choice boils down to personal preference, recoil management, and ammunition availability on your area, as well as the purpose to which the rifle is to be put. We would suggest that while .30-06 and .270 Win do offer extended ranges, the average hunter still encounters his prey within 100-150 yards, making these magnum loadings intended for longer ranges slightly less suitable for close-in shooting. Add in the possibility of using the rifle in question as a target gun, and we would suggest that the more manageable recoil of the .308 Win, coupled with the broad selection of match-grade or target ammunition available in this calibre, owing to its popularity as a target round as well as a hunting cartridge, would make the .308 a more logical and affordable choice for recreational as well as hunting purposes.
Good luck with your purchase, which ever you choose!