Mounting Your Optics

November 25, 2014

Written by: Mark Greer

Let’s talk about “OPTICS”. This subject stirs up a lot of the BIG D WORD!!!Discussion, Dissension, Disparity, Disagreement, Divergence, Divorce… Need I go on???? The last word of the last sentence has been brought about by my next statement, however, I firmly believe in it. “Buy the best glass you can afford!” Now some of you take that further than necessary and this is where the Big D word comes in. It is simple to avoid the “BIG D” by telling your significant other that the piece of glass you “Need” cost double what it actually cost. For example: If the scope you “Need” cost $1500.00, just tell your significant other it cost $3000.00. After a little bit of time (usually about 3-4 weeks for me) I tell my wife I found the same scope for about ½ price ($1500.00) and she believes I really searched the world over until I found the right deal for me and she will usually OK the purchase. Now that we have that wonderful piece of glass that will fix all of our shooting issues let’s get her on the rifle correctly and understand what our purchase really is.

Mounting Your Optics: First let’s get the Base on.
I personally like to again purchase the highest quality Rings and Bases I can afford. Typically when I am able to utilize that type product I do not have to lap rings. First I like to ensure all surfaces that meet are dirt/dust free so as not to put anything in a bind. When I mount a bases to the rifle receiver (for me it is typically a 20MOA angled base) I use locktite products under the base where moisture might be able to creep under the base and get to the base screws. This will prevent rust from occurring on the small screws and prevents an issue if you want to remove it later. Doesn’t take much, just lightly coat the bottom of base where it meets the receiver around each screw hole. Also I use the purple colored product (low Strength) as these are not very big screws. These screws are usually torqued at 22-25 inch pounds. Please note the word inch (not foot pounds).

Now that the Base is correctly placed let’s get the Rings attached. On my rifles almost everything is Milspec Picatinney Rails and using those I don’t have issues with having to align scope rings. If you need to align rings please purchase a set of alignment bars that fit you ring size to align correctly. It will save you from crushing a scope tube at some point and are very simple to use. I won’t go into those here but if you need info on them please call me. Now we want to place the scope in the rings and simply tighten enough to prevent scope from falling off or out. This usually means I can adjust the scope by hand for eye relief and Cant. Ok, now let’s get the scope set for eye relief (distance from eyepiece to your eye). I will shut my eyes and mount the weapon on my shoulder where I am comfortable then open my shooting eye. You should have one clear circle with no shadows in your scope. If you do not see a perfect clear circle move the scope forward or backwards and repeat until you do. (I use a cheek pad on my stock to get my eye on the same height/plane as my scope. Some people like that, some don’t.) You should not have to push or pull your head to make the scope clear for you. It should all fit and be the same position every time. Next I want to ensure there is no Cant or tilt. We want the scope to be aligned with the rifle. I will place a bubble level on my Rail/Base and that allows me to get the weapon straight up and down. Next I place a bubble level or torpedo on the top turret cap and level that. Now our optics are squared with the weapon (at which point I place an anti-cant level on the forward tube of my scope for field use). Now that we have our optics set for Eye Relief and Cant we need to tighten the ring screws a little and recheck Relief and Cant. Here is where I will then torque my Rings to the Base. For good quality steel rings and bases I set it at 65 inch pounds. If your products are aluminum please check manufactures settings. Now after rechecking Cant and Relief torque the ring tops to the bottoms at 22-25 inch pounds.

Only a couple of steps left but very important.
First if your scope is variable power and has an objective focus or side focus knob we need to place it on the infinity setting or highest setting. Next mount the weapon like your shooting it and look through the scope at a white wall or even (do not stare at it for more than 2-3 seconds as your eye will focus it naturally) the clear sky. What you want to look at is the reticle, not the wall or sky. We want the reticle to be crisp and clear immediately. If it is not, simply uncouple the reticle focus knob on your eyepiece and adjust until the reticle is sharp and in focus. Retighten the reticle focus knob and your set to begin a bore sight and zeroing process.
Next time we will talk about the difference in a First Focal Plane Scope and a Second Focal Plane Scope.
“Distance is my friend, for I am trained-my opponent is not.” Author Unknown

Mark Greer’s experience in Long-Range Shooting stems from his military accomplishments as a qualified Airborne Ranger Sniper and Instructor. He continues his instruction expertise through training and consulting in ballistics.