20" AR.Are you shooting a Mini-14? They seem to chuck brass a looong way.
Good, consistent reloads will land in a bucket, if you're shooting from a fixed location (sometimes, at least!).
Place some sort of barrier next to your shooting bench or construct some sort of basket to gather your brass on your rifle. Or just live with it
The firing line right of my position was a bit cluttered with barrels and stuff stacked against a wall last time I was there, so there were plenty of places for the brass to hide. I eventually dragged a piece of plywood over to try to deflect most of them down to the ground next to me. But I see the appeal of a brass catcher.