Shotguns are the utility weapon of the shooting world. With the proper barrel configuration, shotguns are the choice to hunt game birds or take down a full-sized deer. Many states mandate that only shotguns with slugs are legal to hunt deer. These restrictions lead many hunters to wonder if a rifle scope will work on their slug-barreled shotgun.
In general, scopes designed for high-power rifles are not suitable for mounting on a shotgun. Shotgun recoil, the limited range of slug-barreled shotguns, and the short eye-relief of most hunting riflescopes make them unsuitable for mounting on a shotgun. However, many scope manufacturers now offer shotgun optics suitable for both slugs and bird-hunting.
Rifles and shotguns are two entirely different kinds of hunting firearms. Scopes have their place on each. However, it is important to understand the differences in designs and uses of rifle and shotgun scopes.
The Big Three – Why Riflescopes are Unsuitable for Shotguns
Shotguns and rifles differ in several ways. Most of these are obvious, but some are slightly more subtle and may go unappreciated when choosing a scope. The big three differences between a shotgun and a hunting rifle are the most relevant factors that make riflescopes unsuitable for mounting on a shotgun.
Recoil Makes a Difference
Shotgun shooters are always respectful of the recoil of their favorite firearm. Studies have shown that many shotguns loads develop recoil energies that compare or exceed the biggest rifle calibers imaginable. For example:
|Shotgun Gauge and Load||Recoil energy||Rifle Caliber and Load||Recoil energy|
|12 gauge, 2.75” 1-1/2 oz.||45 ft. lbs.||375 Wby Mag 300 gr||47.3 ft. lbs.|
|12 gauge, 3”, 1-5/8 oz.||52 ft. lbs.||375 Ultra Mag, 300 gr||53.2 ft. lbs.|
|12 gauge, 3”, 1-7/8 oz.||54 ft. lbs.||458 Win Mag, 500 gr||62.3 ft. lbs.|
You can quickly see that some standard shotgun loads deliver recoil energy that equals what most people consider elephant guns. Delivering this kind of energy repeatedly to a traditional rifle scope is a recipe for scope failure. You will eventually damage or destroy a standard rifle scope on a shotgun.
The Eye Relief Issue
Most riflescopes intended for large caliber rifles have a relatively short eye relief. Often this eye relief is about 3.2 to 3.6 inches. This distance is adequate, even at higher calibers, for the recoil from high-power rifles. Even then, some unwary shooters unfamiliar with the recoil of these hunting rifles suffer facial injuries when the eyepiece of the scope impacts their face after a shot.
We know that many shotguns deliver the same or more powerful recoil than large-caliber hunting rifles. Imagine the problems of putting your face within that 3.5 inches of the scope mounted on a shotgun. Scopes designed for mounting on shotguns typically feature much longer eye relief to prevent potential injuries and accidents.
Consider the Ranges You Hunt with a Shotgun
Typically, hunters who consider mounting a riflescope on a shotgun are shooting slugs and hunting larger game animals. Before mounting that riflescope on your slug gun, consider the differences in effective ranges and how your scope functions.
Effective range is the distance that you can expect your firearm to perform accurately with enough takedown power to stop the game animal you are hunting. For most rifles used in the US for upland game, the effective distances range from 175 yards to well over 1000 yards.
At best, a slug shotgun fitted with a rifled slug barrel has an effective range of about 75 yards. There are combinations of barrels and loads that allow you to shoot further than 75 yards confidently. However, in most cases where hunters use shotguns and slugs, the effective ranges are between 75 and 100 yards.
A riflescope that is effective on a rifle that shoots easily to 300 yards is probably not suitable for use on a shotgun shooting slugs for several reasons.
- Magnification – one of the great benefits of a scoped gun is the ability to bring your target in closer. However, too much magnification can create problems and safety issues. For this reason, mounting a 3X rifle scope on a shotgun may make it extremely difficult to find or safely shot at your intended target.
- Field of View – As magnification increases, your field of view in the riflescope decreases. This decreased field of view limits what you can see downrange. Too much magnification and your field of view gets so narrow at the usual shotguns distances that you cannot see what is around or beyond your target. In addition, if your target bolts or moves, it may be almost impossible to find and track your target through the scope.
- Reticles – The reticles in hunting riflescope usually have markings for MOA or Mils. These are measures of angles of distance. Trying to estimate distance, windage, and elevation with a riflescope at shotgun ranges is next to impossible.
These issues with mounting a riflescope on a shotgun don’t consider trying to track and shoot a moving target or using a shotgun for wing shooting at game birds. These shooting situations present an entirely different set of problems if you mount a riflescope on your shotgun.
The Solution – opt for a Shotgun Scope
Most scope manufacturers now offer shotgun-specific scopes that match the type of hunting most shotgun shooters perform. These shotgun scopes cope well with the higher recoil energies, offer longer eye-relief, and have reticles that work well with slugs, buckshot, or birdshot.
Shotgun Slug Scopes
In many places, a shotgun and slugs are the only options for hunting larger game animals such as deer. It is not unusual for hunters in these areas to use shotguns with rifled slug barrels and shotgun scopes regularly.
If you consider a rifled-barrel shotgun and slugs for hunting, there are some factors to consider when choosing a scope for your shotgun.
- Quality and Durability – We already know that scopes mounted on shotguns take some tremendous abuse from recoil. Consider the quality and durability of the scope when selecting. Stick with a scope manufacturer with a proven track record of building quality scopes that can take heavy use. Look at the manufacturer’s warranty. Those who have confidence in their products will offer better warranties.
- Accuracy – Some shotgun scope manufacturers are now offering bullet drop compensation scopes for shotgun slug calibers. Adding BDC to a scope gives you the ability to bring rifle-style accuracy to shotgun slug ballistics. Having all the tools in your toolbox can mean the difference between a successful hunt and a disappointing ending.
- Think Outside the Reticle – Don’t get caught up in the conventional thinking of a scope with a reticle and crosshairs. Given the ranges of most slug shotguns, many red-dot sights are perfectly capable of delivering the kind of accuracy you need in the field. Typically, these red dot optical sights are smaller, lighter, and offer unlimited eye relief. This combination of features makes red dot optical sights perfect companions for slug shotguns in many situations.
- Budget – Fortunately, many shotgun-specific scopes offer quality, durability, and accuracy for almost any budget. Doing a bit of homework is key to finding the right collection of features within your budget.
Selecting a scope for your slug shotgun can be challenging, but you can find the perfect match for your needs and your budget with a bit of diligence.
Shotgun Scopes for Bird Hunting
A great debate rages on whether optical sights are useful on a shotgun to hunt game birds. There are compelling arguments on both sides. In our opinion, it boils down to a matter of personal preference and experience.
- The Pros – Those who advocate for optical sights when wing shooting makes several good points. In most cases, a red dot or holographic sight is the choice for game bird hunting with a shotgun. Proponents argue that the red dot is easier to see in relation to your flying targets, making judging the proper lead easier and more instinctive.
- The Cons – On the other side of the argument, those who consider wing shooting more art than science. In their view, successful wing shooters don’t really aim. For this group, the combination of experience, feel, and the view down the shotgun barrel is done intuitively to make successful shots.
Our suggestion is to try it both ways. If you are already a successful wing shooter who makes consistent shots, adding a red dot or holographic sight may not bring you any advantages. However, like many of us who are older and suffering from vision problems, a red dot sight on a shotgun can make a world of difference.
Making the Decision
In the end, it is your decision on whether to mount your riflescope on your shotgun. No one is going to stop you in the field and tell you that you have the wrong scope on your shotgun. On the other hand, mounting your expensive riflescope on your shotgun may end with some bad results.
You risk damaging your scope from the more intense recoil of a shotgun. You may injure yourself trying to find the proper eye-relief to use the scope without adjusting for the recoil. The riflescope may not be suitable at the ranges you will be shooting.
You may find it much more suitable to mount a scope meant for shotguns. In the long run, it may be cheaper and will certainly give your better results and make your hunts more enjoyable and successful.