Many people follow a simple rule of scope buying, without understanding rifle scope basics. They buy a scope that costs a certain percentage of the cost of the rifle. This rule ignores all the rifle scope basics and many times ends up with a person getting the wrong scope overpriced scope.
If all you do is shoot 100-yard targets there is no need for $500 scope on a $1000 rifle. You will most likely end up with more features than are useful. Things like too much magnification. Too big a reticle. Bullet Drop compensation when you never shoot past 100 yards. All money that could be saved or spend towards better lenses with a lower-priced simpler scope.
This means before buying a rifle scope you really need to learn rifle scope basics so you can pick the perfect scope for your rifle and shooting needs, and only spend the money you need to get the scope you that works for you.
Type of shooting
Before buying any scope you’ll need to consider what kind of shooting you plan on doing, with the rifle you’re going to mount it on. There is no one perfect scope for every rifle.
Long Range
The long-range shooter will want higher magnification. Which also means a bigger objective, and possibly a different type of reticle. Long-range shooting is where MIL dots become beneficial. As you’ll want to use them for their ability to find distance easily. You can also expect to pay more because you’ll want a greater quality lenses. Looking through a scope that doesn’t seem to focus is a problem when trying to shoot out to 500-800 yards. Things are small enough at that range without them being out of focus.
Target Shooting
For simple target shooting at 100 yards or less, picking the right scope becomes easier. All you need is a simple duplex reticle, 3-6x or 3-9x power, and clear lenses. Buying a fixed power is a good option as you can spend more on quality and less on the variability of magnification.
Hunting
Riflescope basics for a hunting scope are pretty simple. You will need only enough magnification so you can see what you’re hunting. With the most important thing being that scope can handle abuse and hold a zero. Most times you only get one shot. You don’t want your scope to be off a few inches because you knocked your rifle getting into your tree stand.
Objective Size
When looking at the rifle scope basics, you must consider objective size first. It’s one of the more important aspects of a rifle scope and yet many times overlooked. The objective size of a scope is the size of the front lens in millimeters. Such as a 3-9x 40 has a 40mm objective.
A larger objective will allow more light into the scope when the scope is set on its highest power. This is why a cheaper scope with a larger objective will look clearer than that of a more expensive scope with a smaller objective. You get more light thus giving the appearance of a clearer sight picture.
Be warned buying a scope with too large an objective can force you to raise your scope higher on the rifle and thus making it harder to properly hold and shoot the rifle as you may not get a proper cheek weld. They also tend to be heavier. Ounces feel like pounds after walking a few miles. Generally, you want an objective between 38-48. Objectives of 50 or larger are for 12x or higher magnification and long-range shooting. Of course, don’t forget what was said earlier about a bigger objective making a cheap scope look better. This why many times you’ll see a $75-100 scope with 50mm Objective and 3-9x power.
Magnification
The main reason people buy scopes is for the ability to make things look bigger, better known as magnification. There are a few things to look at when considering magnification, such as fixed vs variable, distances and type of shooting.
Fixed vs Variable
Scopes come two types of magnification, fixed or variable. Fixed magnification is simple. They tend to be cheaper and have fewer parts to break. Whereas variable magnification scopes give you the option of zooming in on your target if you need a better sight picture.
How much magnification is needed
Determining how much magnification is needed is really more of a personal choice than anything. In reality, 3 power is good enough for anything under 100 yards, with more needed the further you are shooting. What you really need to be concerned with is your field of vision. You want to be able to see some details of what you are shooting without having so much magnification that all you see is a small section of what you are aiming at. This is really where variable power scopes shine. You can turn the magnification down so you can easily find your target then turn it up to get more details.
Something to consider is that the more power you have the more your reticle will move around on you while you are aiming. In fact, too much magnification and you may see your heartbeat in your scope. This is why many people will tell you less than 9 power for shooting off-hand and more than 10 power for using some sort of rest at longer distances.
Reticle
The reticle is the aiming device in the scope. There are countless different reticle styles, however, most of them are based on three main types, BDC, Duplex, and Mil-Dot.
Duplex
Duplex is the simplest reticle. It’s also the most common one. It’s simply crosshairs. They are thicker on the outside and get thinner as they cross. This sort of forces your eye to the center making it easy to hunt with, and perfect for target shooting.
Mil-Dot
The Mil-Dot reticle is for ranging. They are for ballistics calculations and finding distances quickly. Each dot in the reticle is a Milliradian (Mrad). 1 Mrad is equal to 3.6 inches at 100 yards. Sort of like 1 MOA is equal to 1 inch at 100 yards.
These reticles have been common on military sniper rifles for their ease of determining distance and bullet drop. For many years hunters have avoided them, but recently more have started to use them for long-distance hunting.
BDC
BDC stands for bullet drop compensation. These reticles have multiple lines under the standard crosshairs that represent how far the bullet will drop at different distances. So if you sight the rifle for 100 yards and you know that you are shooting at 200 yards you’d line up one of the lower lines with where you need to hit. Thus you don’t have to adjust your turrets to adjust for bullet drop.
Some BDC reticles are caliber specific others require you do some math based on MOA to determine bullet drop for your caliper. Before you buy a BDC scope find out how they mark the bullet drop.
Turrets and adjustments
Scope turrets adjust the reticle to match the trajectory of bullets shot from the gun. This is called zeroing the rifle scope. They can also be used to adjust for windage and bullet drop at different distances.
There are a lot of different styles of turrets. The biggest difference between them comes down to can you adjust the turret with your fingers or do you need a tool of some sort.
Of course, when adjusting your scope most turrets adjust in clicks. How much each click equals varies to the individual scope. The most common adjustments are labeled in MOA. With Mrad’s as the next most common.
MOA
MOA adjustments are based on 1 MOA being equal to 1” and 100 yards. This means when your scope turrets are labeled 1/4 MOA adjustments. Each click will equal 1/4” of adjustment at 100 yards. Of course, if you’re zeroing your scope at 200 yards they will be equal to 1/2” adjustments.
MRAD
MRAD adjustments are based on 3.6” at 100 yards. Doing the math a 1 MRAD adjustment moves your reticle a long way. This why these scopes are preferable for long-distance shooting where you don’t want to run out of adjust before you have compensated for bullet drop and wind drift.
Focal plane
The focal plane refers to where the reticle is mounted as compared to where the magnification is. It’s only important when dealing with a variable magnification scopes.
First focal plane
First focal plane (FFP) scopes have the reticle mounted in front of the magnification lenses. This means as you adjust the magnification both your sight picture and reticle picture will get bigger or smaller. This is perfect for MIL DOT and BDC reticles as they will be the same no matter what magnification your scope is set on.
Second Focal Plane
Second Focal Plane (SFP) scopes have the reticle mounted behind the magnification lens. These are perfect for simple duplex reticles. As you reticle picture doesn’t change with magnification. However, it does mean that your MIL DOTs or BDC will change value on all magnification except the highest magnification.
Eye relief
Every scope has some eye relief build in. If they didn’t you’d have to have your eye right next to the scope when shooting. This is not a good idea as the recoil of the rifle would put the scope into your eye. Since you can adjust for various scope eye relief by mounting the scope farther away or closer. You don’t have to have too much concern about how much eye relief a scope has. Unless you have a limited place to mount your scope. Just keep it in mind when looking at scopes because if there is too much eye relief you may have to shoot with your head in the wrong position.
Parallax adjustment
Parallax is when the focal plane of the object in the scope is offset from the reticle. This is best seen when you move your head just a bit and the crosshairs seem to move in the scope, compared to the target. This is not normally a problem until you start shooting at long distances.
Most scopes have a fixed parallax because at lower magnification the very small of parallax doesn’t make a lot of difference. It’s when you get to 10x and above that, you want to have a parallax adjustment on it.
Red Dot and Reflex with magnifiers
Red Dot scopes are powered scopes with a simple red dot in the center. They have no worry about parallax. They are perfect for quick target accusation. Most are either zero magnification or just a 3x.
Reflex sights are a lot like the red dot however they work more light a heads up display. The dot will move around in your sight picture, just like your target will move any time you move the gun. Reflex sights are not magnified. However, you can get a magnifier to mount with it.
One thing to remember when looking at either a Red Dot or Reflex is the size of the dot. They are rated in MOA dot size. So a 2 MOA dot means if you were aiming at something 100 yards away the dot would cover a 2″ circle. As most people don’t shoot 100 yards with a red dot or reflex it’s not as bad as it seems, but something to be careful of.
Price Point
With rifles scopes, there is no hard and true price for a scope. You can’t just say spend 1/2 of what you spent on the gun. The price of the scope will depend on the features you want and the quality of those features. Nowadays you can’t even claim, just buy a scope from a certain manufacturer. Every manufacturer has their line of budget, lesser quality scopes and their high-end, expensive scopes. Which means you just buy a scope with the features you need, in the price you can afford. Remembering sometimes you have to give up certain things to better quality on other things that really matter in your price range.
Conclusion
Once you understand the rifle scope basics, you should be able to pick the scope that is perfect for your rifle. With all the options when buying a scope you can’t just say one scope is perfect for everyone. You’ll need to consider what type of shooting you do. Which will determine the objective size, reticle style, and magnification needed. From there you’ll look at turrets, focal plane, and if you want an adjustable parallax. Last you look at price and what want versus what you can afford. Remembering you get what you pay for. The simple understanding of rifle scope basics makes all the difference between cheap scope you hate, and quality scope you love forever.