i'm having a hard time getting my harris bipod legs to hold on the concrete bench. adding some fabric still allowed it to slip. I plan to carry my rifle with the bipod and shooting sticks so i'd prefer to practice with them at the range. so, what type of tricks do you have for being able to load up the legs without having them slip out? this problem has been causing my rifle to jump to the bolt side consistently and need repositioning each time for follow-up shots.