I mounted the Burris 2x7 LER on my 357mag. new model ruger blackhawk,Im having a problem grouping. The scope has a parallax adjusting ring on the front. Ihave tried several handloads,factory and .38 in the same. I have a Burris 2x7 on my contender,it doesnt have the parallax adjustment and it groups perfect out to 100yds. The 2x7 LER I think is an older scope,its steel and its heavy. What should the parallax be set at. I can only turn the power ring up to 4 then it starts to black out unless i move my eye closer to the scope. Is it the wrong scope for the gun. I recently picked it up at a local gunshop (used). Im trying to get a group at 25yds. Im open to idea's.