For me I would say “long range” is dependent on position and wind. I’m fortunate to have a public property range where I can shoot anytime from 200-900 yards. I practice all field positions there and have developed MER for these positions. Each position’s MER is lengthened or shortened based on wind. Perfect example was a mule deer hunt last season. Had an opportunity on a buck, bedded cross canyon at 500 yards. Position was very comfortable prone on the rim of the canyon. My prone MER is 500 with wind 6ish max. In this case there was a 20+ mph wind from roughly 1:00. I did some mental calculations and came up with a windage solution that was so wide that I never seriously considered pulling the trigger…the range was too long for me.
The next day I killed a buck a couple drainages over at 512. Prone, cross canyon, lots of time, wind sub 4mph. I felt comfortable taking the shot, but it was definitely “long range” for me.
For a guy shooting thousands of rounds a year at long distances that may have been a “chip shot”. For someone who doesn’t have access to that kind of shooting it might be considered impossibly long.