I just bought a couple Harris 6-9 Swivel bi pods with the notched legs. I have tried them on 4 different rifles. My 3 Accumarks and my ever faithful Ruger 77V. All 4 rifles it changes my point of impact 1 1/2" up and turns 1/2 inch grouping guns off of the bags into 1 1/2 to 2" horizontal stringing messes. The 22-250 is not that bad but it still changes the poi by an unacceptable amount. I have tried a variety of rear rests, different holds and nothing seems to work. I bought them after reading about all these precision shooting results I have seen on this sight and others. I tried the same Harris in the 9-13" model before I bought mine. On the bench it was just too tall but it did the same thing. I thought it was because it was too tall. The 6-9" seem very steady. Looking through the scope and dry firing they are more stable than my sand bags. 2 of my Accumarks are very generously free floated clear to the action. There is no stock pressure on these two at all. Right now the only thing they are good for is taking pictures and holding the guns for cleaning. I have had several other people shoot them with the same results. Their Harris bi pods seem to work fine. What the heck is going on with mine? I always cover my shooting table with a blanket. Could that be causing the problem?