The textbook method for mounting a scope requires some equipment a lot of people don’t own. Most people have a rifle, a set of scope rings, a scope and whatever tool (be it a screw driver or Allen wrench) is necessary for attachment, and that’s about it. Fortunately, regardless of what manuals and other documents specify, those items are enough to get a scope mounted.
First, attach the rings to the rifle and make sure they are sufficiently tight. There has been a lot of talk in the last few years about scope ring alignment (making sure the rings are perfectly aligned with one another), but for the purposes of a hunting rifle I’ve never seen any rings far enough out of alignment to be of concern. Perfect scope ring alignment is more of an issue for target or competition shooters and, for the most part, the casual shooter or hunter can ignore a small amount of deviation.
Next, mount the scope in the rings with the screws tightened down enough to hold the scope in place but loose enough to allow for movement if a small amount of force is applied.
Check to make the scope’s eye relief affords a complete field of view with no black rings in the sight picture. Move the scope forward and backward in the rings until you find the proper location. Be sure to check this in both off-hand and prone positions to be sure you’ve found the scope’s “sweet spot” for your particular eyeball. Once you’re happy, mark the location of the rings on the scope with a black marker. These marks will help you keep the scope where you want it and will wash off after a few hunting trips in the rain.
With the eye relief set you can now rotate the scope side-to-side to level the crosshairs. First, pull back from the scope so that the reticle is visible and align the vertical crosshair with a part of the receiver you know to be vertical, or until it evenly divides a horizontal portion. This “eyeballing” technique is simple, but is very effective in practice.
Check alignment by once again bringing the gun to your shoulder in the off-hand position and tweaking as necessary. If it seems canted or uncomfortable you will be able to make the necessary minor adjustments.
Finally, tighten down the ring screws in small increments, alternating from side-to-side and ring-to-ring to keep the scope from turning in the rings. With the scope locked down a small amount of eye relief adjustment can be made on most models by turning the rear eyepiece.
At this point you should be ready to take your rifle to the range and get it sighted in.
Enjoy your newly mounted scope