Re: Remington 700 5R .308 or Remington 700 5R .300 Win Mag???
Never owned the 300 version but did own the 308 5R. It was awesome. The 11.25 twist will handle up to 210 grain bullets. Believe it or not, 11.25 is very optimal for the 190 smk. Any modern twist calculator will back this up. I regularly took the 175 and 190's to 1000 yards. Even at near sea level and sub zero temps they punched perfect holes at 1k.
For just practice, it's hard to beat the 308. Long barrel life, easy on the shoulder, cheap to reload for, easy to load for, accurate as he!!. In my mind, for the purpose you're asking, it's a clear choice. Not to say the 300 wouldn't be good, just the 308 is so versitle when one needs a 'practice' rifle. Even if it is at 1k. It's less forgiving in the wind but that's a good thing when you're just practicing. It really makes you focus on the wind better.
My old 5R 308 was wicked accurate. I've heard a lot of similar statements over the years.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.