Go to Offline Training, or the Training Arena, and use the .target command so you can see it.
.target xxx, where xxx is the distance you want the target, will put a great big target to your north at that distance. You can put your pipper on the center, and see how far the bullets drop when they hit the target.
.target 400 will put the target at 400 yards. .target 0 makes the target go away.
There are more variables you can use with the .target command, but this should be enough to tell you what you want.