I have a feeling I am going to need to shoot this new handgun of mine with a 9-13" Harris bipod and that puts the rear of my gun off the ground about 4". I need a rear bag. I found myself squeezing the bags at the range and this worked pretty well. What do you guys use and where can I purchase one or get more info? I'm looking for something to use in the field and weight isn't really important cause I'll probably get a few and fill one with sand and one with something lighter.