That's funny, considering just about every gun action out there was developed to make it a more efficient man killing machine than the technology that came before it. Matchlock lead to Flintlock, Flintlock to Percussion cap, Percussion cap to a self contained cartridge, which led to trap door Springfield's, rolling blocks, lever actions, bolt actions, pump actions, the Gatling gun, the advent of smokeless powers, then along came auto-loaders and full auto actions.
They ALL have one thing in common. They started out as machines of war.
Optics up until recently haven't been all that reliable in battlefield conditions, so they were sort of an afterthought for most black guns. That has changed. Most modern battle rifles use a flat top receiver now and incorporate some sort of optic with a back-up iron sight. My Eotech on my M4 is awesome and my next purchase for it will be a matching magnifier. But should it fail, I can co-witness my iron sights right through the Eotech's sight window. It's all very fast and I don't have to crane my head way up off of the iron sighting plane.
Then I suggest you strap a barrel to a Steinway...
Yeah, a bolt action .30-06 or .308 will cover all of that territory. But it would be overkill for some things and MARGINAL for something like a Kodiak or Polar bear. And that price point would be tough. Good rifles aren't all that cheap and neither are good optics. Buying used would boost your buying power, but again, GOOD sighting options aren't cheap.
Now, what if you're hunting some 1000lb+ Kodiak and he surprises you with a charge? My G3 would be ready with a lightning fast action and low recoil, twenty rounds of .308 (negating much of any perceived marginality) in the quick change box magazine and the speed of my co-witness irons as he charges in from close range. Try that with your elegant bolt action...
I bought everything, including the scope and mount, for your price point of $750.00. Plus, I think it looks fucking cool...