I do not own a S&B scope but I have read several reviews that this very normal on these scopes.
I stand to be corrected though............
HW97 V-Glided with LP Eliminator Stock Big Nikko 10-50x60
TX200HC V-Mached with LP Eliminator Stock Tasco Custom Shop 8-40x56
CZ S200 FT Stock Big BSA 10-50x60
AA Shamal Big BSA 10-50x60
Steyr LG110HP HFT Modded EB Sniper