Alright, here we go. Who needs to do math when you can use an online ballistics calculator. Plus, this way I can use the drag coefficient as well.
-velocity 1000fps
-bullet weight 5 grains aka 0.33g, a common airsoft sniping bb weight
-range is in yards
-drop is in inches
-ToF = time of flight
-and energy is in ft lbs.
This is what I feel would be acceptable for gaming. At 100 yards, it has lost almost all energy, so this is about the maximum range. A 100 yard max range is decent for games. You would rarely shoot farther than that. At 100 yards, the drop is 50 inches. A high end Schmidt & Bender scope will give you a 56 MOA adjustment, so if zeroed properly, you would just be within the scopes range. But, I'm guessing most people wouldnt take the time to adjust the scope that many clicks. It wouldn't be that hard to just guesstimate 4 feet above the target and shoot. So, these ballistics sound pretty good, except...... muzzle energy is 11.2 ft lbs. which is over 15 joules. Just a little over field limits :-D 1.5-2 joules is a common outdoor limit. This would also make it a firearm, and would have to be licensed. It would also then be illegal to point at a person.
So there you go, to get an acceptable trajectory, the energy would just be way too high (and illegal).
If anyone needs clarification on anything, just ask.