...Of course we don't know the caliber of the rifle but we have to assume it's better than a .223 (which works at 100 yards IMO), but if you look at comparative ballistics charts for any cartridge of substance, the ballistics will show a marked climb in trajectory (bullet rise) past the 100 yard zero and then the drop (as the velocity degrades and gravity takes over)......
Much better off at 200 or 300. I realize that most ranges (at least around here), benchmark at 100 yards so it becomes a matter of finding a range or a field where it's plausible to set a target at 200 or 300 and sighting in for zero at that distance.
As with any object (in this case an optic) that's mounted higher than needed, harmonics and recoil forces come into play. The higher the optic, the more chance for error (why I don't care for the 'shoot through rings'IMO) and to a lesser extent, the handrail mounted optics on an AR. To me, perching a scope way up there is asking for error..... probably why I'm not a fan of that platform in the first place.....
You want the objective bell as close to (without physical contact) the barrel as possible. Remember, the optic don't move, the erector system inside the optic moves when you dial the elevation up or down or the windage back and forth.....
The are some variables involved in that aspect as well, one of the variables is how you sight through the optic in relationship to the stock itself and how you position your cheek (cheek weld) to the stock when using the optic but for practical purposes, the closer the better.....
I keep various height ring sets in the drawer so I can acclimate my preferences to a particular rifle in relationship to how I sight through a scope on a particular rifle...... That's why (at least for me), ordering a set of rings for a rifle is trial and error, like buying a set of shoes without ever trying them on. If they aren't comfortable, you don't wear them. Same applies to rings.
Everyone is different in the way they hold their firearm and sight through an optic. Just like eye relief and it's relationship to the shooter. Everyone is different. What works for me, may give you a black eye...or worse.