Scope is the VX-3 (not III) which has only been out a couple yrs. They have screw off caps unlike the Mark V, they are about 1.5", black with numbers on the side. Sounds like the 3 little allen screws are the right thing to do.
Yes it sounds like you have the same model as mine If you will search this site and look up a thread that I started Titled : "752 yard 3 shot group" you will see a pic of my scope and rifle , then we'll know for sure .
bassin93 post is spot on do it exactly like he reccomended and you should be good to go .
bigBuck