@gungasnake,
I dont think 1,000 m ranges are good for anything but area fire and that is possible with standard ammo anyway. Heat haze, and the need to aim up which places the barrel over the view of the target make anything over 600 m very difficult.
At 1,000 m ranges, the WWII bren gun was actually so tight it could be used for sniping in the desert of a night time. There was also an instance where an Australian won the Victoria Cross by taking out several machine gun bunkers. He simply aimed and fired and every round went into the slit killing all the crew inside.
This accuracy made it less useful as an area weapon, the main point of having it so it was re-equipped to have more windage which in turn made it less accurate but more able to suppress the enemy.