Hi guys I was at a flea market over the weekend and picked up a TC pistol scope 1.5 RP with target turrets #8302 in the original box. This scope looks like it is brand new. Paid $25:00. My question is the rear eye piece will not turn to clean field of view , it has the rough part to get a hole of put I can not turn it , I afraid that I will broke it . Can anyone help with this, is it made to turn????