Unfortunately it is hard to find a gun range with a distance beyond 100 yards in Minnesota, but I had the opportunity to shoot my Spanish Airforce Mauser in 8 MM routinely at 200 yards, using around an 8" drop correction, with open sites using surplus ammo 10 years ago. The bore was corrosion damaged and worn, but most of the shots went into the black on the typical pattern 25 yard NRA pistol target, I could not see the target, but had to guess where it was using the target holder.
Finland's war hero of the Winter War, Simo Hayha, used a Mosin Nagant model 28 with open sites at ranges of around 400 yards to kill numerous Russians. A 62 year old fellow by the name of Farr, used a match grade Springfield 03' with open sites, and surplus ammo to repeatably hit the 1,000 yard target at Camp Perry in the 1930's. If you know the rifle, have good eyesite, and decent wind conditions, yea, long range is not so hard.