How To Choose A Rifle Scope For Deer Hunting

By Archer | Scope

Apr 01
Long Hunting Riffle

So you want to get yourself a sizable deer, but can’t get close enough without scaring it off? I can’t tell you how many times I’ve been in that situation. Sure, the simple solution is to shoot from further away, but how accurate is your shot then?

Very accurate, if you get the right scope.

I’ll let you in on a little secret. The scope makes a big difference. So if you want to make that shot you see the characters do in movies, you need to add a scope or change the one you already have. Here’s my 2 cents on what to look for and how to choose a rifle scope for deer hunting.

Hunting Rifle With Scope
Image Via Flickr CC: Wisconsin Department of Natural Resources

 

Matte: All That Glitters Is Not Gold

I’ve once had the perfect shot on a deer, but as I was about to pull the trigger, the sun crept through the trees and a glare bounced off of my scope. Goodbye, deer.

It’s simple. If it shines, don’t bother. Your best bet is to get a scope with a matte finish.

Magnification: Zoom, Zoom, Zoom

The whole purpose of getting a scope is to be able to see from far distances. But how far do you have to go, really? I suggest you stick with a 3-9×40 scope. Not sure what the numbers mean? It’s really simple!

3-9x means that you can adjust the scope to magnify your sight anywhere from 3 times to 9 times.

The 40 refers to the diameter in millimeters of the objective lens (that’s the lens opposite of the one you’re looking into).

3 to 9 times by 40 is the way you would say 3-9×40.

There are scopes that have a stronger magnification, some even going up to 20x. But you’re trying to shoot a deer, not a mouse.

Also, think about how you shake as you try to steady your aim. Can you imagine how chaotic that tremor would look through a 20x magnified lens? The slightest movement could throw your entire shot off.

Hunter On The Prowl With A Hunting Rifle
Image Via Flickr CC: David Cockburn

Eye Relief: A Whitetail for the Cost of a Black Eye

The first time my dad let me shoot a rifle was through a scope. I had my eye pressed right into the lens and squeezed the trigger. The recoil hammered the eyepiece into my face, leaving a small bruise above my right eye.

Make sure that the scope for your rifle offers you space away from the scope while still giving you a clear picture. This space is called “eye relief.”

The standard is 3 to 31⁄2 inches.4 inches is the most you can get for eye relief which is more than enough space to prevent injury from any recoil your rifle kicks at you.

Exit Pupil: What You See is What You Get


Just because you have your cheek on the rifle and can see the lens doesn’t mean you can actually see through the other side. You have to correctly position your face to actually see from the eyepiece through the objective lens. If misaligned, you won’t see a thing.

Don't Risk Taking An Illegal Shot - Know The Difference Between A Mule Deer and A Whitetail Deer
A Mule deers antlers fork in two directions as they grow, splitting again to create more tines (points). Whitetail deers have one main beam from which all other tines emerge.

Remember the 3-9×40 we mentioned earlier? Those will have an exit pupil size of 13.3mm (at 3x magnification) to 4.44mm (at 9x magnification). This is the standard pupil size range.

There’s a formula to quickly find the exit pupil of a scope, and that is to take the diameter of the objective lens and divide it by the magnification. For example if you have the 3-9×40 scope, and you want to find the exit pupil at 3x magnification, you would take 40 and divide it by 3. Easy, right?

If these numbers mean nothing to you or you simply don’t want to deal with the math, you can actually see this by holding the scope out at arm’s length and looking through the lens. You’ll see the small circular light (the exit pupil), and when you adjust the magnification it’ll get bigger (as you zoom out) and smaller (as you zoom in).

In short, if the exit pupil is big, you can correctly position your face quicker and easier. If it’s small, you may have to read just your face positioning a few times before getting the best picture through the lens.

Light Transmission: Don’t Shoot in the Dark

Let’s get one thing straight. Scopes don’t gather light. Light transmission gives your scope the ability to use the light in the environment.

Anything above 90% light transmission is fine, above 95% is great, and above 98% is pristine. However, if you’re on a budget, don’t feel like you’re missing out too much by getting a scope with 90% light transmission. In my opinion, that’s good enough.

**If you are planning to hunt at night, check out our reviews on cheap night vision scopes here.

Lens Size: The Bigger the Better?

A bigger objective lens means more light transmission which means you’d get a better shot, right? Not necessarily.

A bigger lens doesn’t just add more light transmission. You have to take into account the size, the weight, and the high mounting required for larger lens. The size of your lens factor into your ability to shoot comfortably. The most common objective lens size is 40 – 44 mm.

TLDR: How to Choose a Rifle Scope for Deer Hunting

The best advice I can give to you is to not over-complicate things. You can get the scope with the best specs, but if it changes your shot too much from what you’re used to, it won’t be worth it. It’ll feel cluttered, overwhelming, and although you may be able to see clearly, you might not feel the most comfortable.

You should start with the standard specs and build up little by little from there. I’ve bolded them in each section, but for easier reading, here they are in bullet form.

  • Your best bet is to get a scope with a matte finish
  • I suggest you stick with a 3-9×40 scope.
  • The standard eye relief is 3 to 31⁄2 inches.
  • Standard exit pupil range is 13.3mm (at 3x magnification) to 4.44mm (at 9x magnification).
  • Anything above 90% light transmission is fine.
  • The most common objective lens size is 40-44mm.

Happy hunting!

About the Author

I love adventures and the great outdoors!

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