I need some collective wisdom. I have a CVA Optima V2. Sighted it in 2 yr ago with a Nikon Prostaff 3x9 BDC and it shot really well. Didn't touch it last year due to injury. Took out today and it shot2" low @ 100 yds. Tried elevating 2 " and it shot the same. Raised it 2 more inches and stayed low, no upward movement at all. What gives? How an anything happen to it when all it has done is sit in gun safe for 2 years?
Try tapping the adjustment screw, with the plastic handle on a screw driver. See if that works. After season send it back to Nikon for repair. Also try turning the adjustment both up and down to see if that helps.
If it doesn't move after tapping the turrets and moving them both around, you could try shimming the rear ring for a temporary fix. A shim or two cut from a soda can and placed between the ring and scope should raise it enough to get you close to zero.
As stated before, if it is grouping, sounds like a scope problem that needs to be addressed.
I fired many shots trying to zero and swabbed after each shot. That's the same technique I used originally when first sighted in. I'm using 100 gr (2 pellets) with 250 gr Barnes all copper sabots. Will call Nikon and post their thoughts after doctors visit this PM. Also after trying to adjust with turrets I shot on second circle (BDC) and made no change in point of impact. So really sounds like scope issue.