I am looking at getting a real rear bag this year for F class. I had borrowed several friends large heavy bags at different shoots and when they are loaded w/ the "heavy sand", they really did make a difference in my scores at 1000yds due to the incredible stability. Anyone ever try the SEB Bigfoot bag? seems to be good and affordable. Also, if you did did you get the one w/ twisted ears to either side and are you glad you did?