After seeing some posts in Aces High concerning this vehicle, I decided to look at it off line.
 Found I could hit targets way, way out there 

Yesterday evening, I decided to try it on line.
I had a 45 minute sortie.  My first kill was two shots for a kill at 4,000 yards.
The next kill was at 3,800.  Virgle was probably not a happy person.  All the hits hit the top of the vehicle, a WRBL.
The third kill was an M4 at 3,800 yards, two hits back to back.  
Six minutes later, redctchr was killed again, this time at 3,900 yards.  
I was on a hill and they were on the opposite hill.  I was well hidden under some trees and all hits appeared to strike the top of the vehicles.  
I never received any return fire.  I guess they did not see the rounds coming in and dropping on them.