I have a father-in-law that can’t seem to put a deer down hard at 25 yds. I know other people who simply shouldn’t take a 100 yd shot.
Between the ages of 15-25, I shot a .25-06 that shot much inside minute of angle. If my rounds didn’t overlap at 100 yds, I considered it a flier. My rifle skills were excellent. I shot prairie dogs at 500 yd and more than once I opted to shoot a standing deer in the upper throat at 200-400 yds (because I didn’t like a messy field cleaning job.
I never took a shot at a deer in excess of 500 yds, but I did pass on shooting a prone shot at a large buck that was laying down. To this day, I’m very certain that I would have hit heart and lungs.
So, what is an appropriate shot? One that the rifle and you can reasonably make with high confidence. I’m not as confident now as I used to be, but I wouldn’t hesitate on a 400 yd steady shot on heart and lungs.
If you have the proper equipment and the skills to use it I see no problem taking game at long range. I was at the range today speaking with a friend whose father 68 yrs old took his elk at a little over 1000 yards. A neighbor of mine shoots coyotes at 800 yards to keep his skills honed. Back East people would never consider a long shot because there just aren’t many places to do it or develop the skills needed to shoot the distance. Out here a person can practice at 1000 yards in their yard as I sometimes do. This season there were 9 antelope taken on the property here at distances of 500-1000 yards, one was taken with a 7mm SAUM pistol.