After about 50 rounds of .308, my groups would shift to the left about 1"-2" at 200yrds. Still tight groups, just baffeled me. Well it was my Harris bipod shifting on my flat bottomed B&C stock.....Straightened it back out, groups returened to where I wanted them. I ordered a #9 Harris adapter to tryout, anyone have success using one of these?
http://www.harrisbipods.com/HB9.html
http://www.harrisbipods.com/HB9.html