A Mauser M18 is a great option. It's also nitrided, so it's sort of a half-ass all-weather option people don't know about. I very much want all guns I (personally) purchase to be either stainless, or some sort of weather-treated alloy steel. These features won't make a gun rust-proof, but you won't have "oh crap did I oil the rifle before I put it away?" pop into your head at 11:30. Or if you do, you can rest easy and remember to do it in a day or two.
The Cz557 is also a great option. I worked at a range where a customer, who was a new shooter, had one of the old 557s that had to true Mauser action. It shot like 1/4 inch groups at 50 meters. I offered to buy it every time I saw him and his son and he never gave it up.
I have never heard anything bad about the Howa rifles, other than their over molded stock can be too soft. Weatherby is also a great bet.
I agree with the sentiments that modern budget bolt guns don't have the design integrity that older guns do, but they do (generally) have superior metallurgy, heat treatment, and stress relief. Those factors can, to some degree, make a mediocre design "okay enough." Nothing can make a bad design good (the Remington 770, new generation of R51, and many other guns they used to make stand out as examples), but some of these budget designs are okay. I would say stick to the level above budget and you'll probably save yourself some concern in the long term.
If you're shooting out to 400m, consider .270. It's underrated these days. 6.5 CM is great for shooting at range, and would probably do what you want well. Consider the price difference in ammo between calibers, because even if 6.5 CM shoots 25% better at range than .308, if you can shoot 2x (this and the 25% are made up statistics, you'd have to look up specific loads for a valid comparison) as much ammo with the .308 for training, it'll be better to go with the option that allots more training. Either way, with modern loads and common sense about choice, most calibers are fine at the ranges you described.