This may sound a little strange, but I use the Marauder or Discovery to regain my confidence that it's the rifle and not the shooter(or vice versa) to blame for bad groups. What I mean is that I love to shoot the springers...but when my groups degrade, i pick up the Marauder or Discovery. Usually, I find that my shooting is pretty good, but it's the idiosyncrasies of springer or gasser (if you will) that are causing the groups to widen. Sometimes I can't hold a group with the M or D...meaning it's time to stop shooting for the day.