Depends on the setup and the shooter. safety and ethics are two different things. The origins of long distance shooting had shooters using open sights at 800yds+. Would it be ethical to shoot that far on an animal? No. The longest shot I would take with an iron sighted gun and feel confident in hitting vitals is 250yds max.

Hope your better than me. I have done a lot of iron site shooting in my life, but mostly small cal stuff like 22's bb-guns and an occasional rifled slug shotgun barrel and black powder gun and I wouldn't even consider shooting 250 yards iron site at a deer unless I was starving to death. Im not trying to hit the silhouette of a sheep at 250 yards, Im trying to hit a deers heart.

You might need to clarify your question.

Are you guiding, and consenting a shot on an animal?
Are you a range owner, and allowing people to shoot targets?

For clarification I ask as the manager of a shooting range and have concerns for safety first always. I have been a shooter all of my life and have my self many times watched where shots hit and kept raising my point of aiming until I could get on the target. On the range I have concerns for "Awesome" shooters wanting to see if they can hit the bulls eye at great distances with their open sight rifles and what ever condition and age eyes. I require demonstrating zero and proficiency from everyone and wonder how far to let someone try to aim high enough to get to the next distance without putting the bullet over the berm and into the unknown. I know there are exceptions to everything and just wanted some general guideline ideas and comments.

Thanks for replying

I require demonstrating zero and proficiency from everyone and wonder how far to let someone try to aim high enough to get to the next distance without putting the bullet over the berm and into the unknown.