I would call ******** on the 400 meter archery shot. Maybe she hit it with a rifle? LOL The distance you start with will depend on what sights you are using, or how many pins you have. If you have an adjustable, single pin sight, you can start at 10 meters and work back to a comfortable distance in 10 meter increments. If you use a more common fiber optic pin sight, you have have anywhere from 3 to 7 pins. I would start at 20 meters (or yards) and work your way back in 10 meter increments. If you only have 3 pins and if you want to stretch the distance with lots of practicing , you could go 30 meters, 50 meters and 70 meters. You would really need to be proficeint with your set up and know where your arrow is hitting at the "in-between" distances like 20, 40, and 60 meters. If you notice the main theme of my post is...practice!! One of the most important aspects of archery is to have fun and push yourself. Don't let yourself get bored by practicing only in your back yard at 20 yards. Change things up, shoot from different angles and different distances. Shoot with a buddy and push each other. Bowhunting is such an awesome sport that really requires honed skills. Good luck and have fun. By the way, what bow are you shooting? Tell us about your setup.
