Shotgun recoil is much like the game “two for flinching” many of us played as kids. The game’s premise was to fake like you were going to punch your buddy, they flinch, and receive two punches on the shoulder as a penalty. It may not initially hurt, but your shoulder would become sore if you played long enough.
Shotgun recoil has a similar effect. Every time you pull the trigger, the firing pin strikes the primer of the shotgun shell and ignites the powder inside the hull, resulting in a mini explosion. That causes the shotgun to recoil, sending the buttstock into your shoulder. If you only shoot a few loads, there will be little, if any, pain. But shoot an entire case of shotshells (250 rounds), and you will end up with a bruised shoulder.
Recoil is unpleasant. But you can measure how much free recoil a shotgun will produce with specific ammunition using a simple mathematical formula (more details on that later). Once you can predict recoil, it may change how you think about shotguns.
Types of Recoil
There are two types of recoil: free recoil, which can be measured using a mathematical formula, and perceived recoil, which is the amount of recoil you feel. Free recoil factors in shotshell charge weight, muzzle velocity, the weight of the gun, the weight of the wad, and the amount of powder in the shotshell. The result from that formula is a measurement in foot-pounds of recoil energy.
If you’re averse to mathematical calculations, this website does the work for you. All you need to do is insert the payload weight, muzzle velocity, and gun weight, click “calculate,” and you will know the amount of free recoil produced.
Gun Weight vs. Free Recoil
We have established that shotshell payload and muzzle velocity, combined with the gun’s weight, determine free recoil. As a gun’s weight increases, free recoil is mitigated. Here’s an example. Let’s use a standard 12-gauge, 1⅛-ounce target load with a muzzle velocity of 1,250 fps as our control to see how much free recoil is produced relative to gun weight.
- Gun weight: 7 pounds
- Free recoil: 24.9 foot/pounds
- Gun weight: 7½ pounds
- Free recoil: 23.2 foot/pounds
- Gun weight: 8 pounds
- Free recoil: 21.8 foot/pounds
The data above shows why most skeet and trap shooters select a heavier shotgun. When shooting hundreds of rounds a week, the less recoil a target shooter experiences, and the more accurate they will be.
Recoil reducers that insert into the stock of your shotgun and recoil pads that fit onto the buttstock can also help temper recoil. You could choose to shoot a shotshell with lower muzzle velocity as well. Let’s use a 7-pound shotgun as our control and see how muzzle velocity impacts free recoil.
- Shotshell: 1⅛-ounce, 1,250 fps
- Free recoil: 24.9 foot/pounds
- Shotshell: 1⅛-ounce, 1,150 fps
- Free recoil: 21.5 foot/pounds
- Shotshell: 1⅛-ounce, 1,050
- Free recoil: 18.3 foot/pounds
Lowering payload weight has the same effect as reducing muzzle velocity, and are the two most efficient ways of mitigating recoil. You can also switch to a sub-gauge, which offers a variety of lighter loads than a 12-gauge. But be careful that your sub-gauge shotgun isn’t too light. A 6.5-pound 20-gauge could produce more recoil than a 12-gauge if it’s paired with a shotshell that has a heavy payload and high muzzle velocity.
The Venturi Effect and Recoil
If you shoot the same load through the same gun, inserting a tighter full choke (as opposed to an open improved cylinder) will increase free recoil because a more constricted choke speeds up muzzle velocity. The Venturi effect is responsible for this.
Think of water passing through a garden hose or putting air in your tires. The water or air comes out faster because it’s passing through a restricted area. Shot moving through and exiting a full choke can be 50 to 70 fps faster than that of an improved cylinder. With more muzzle velocity comes increased free recoil.
How to Handle Perceived Recoil
Perceived recoil is subjective. For example, if a 10-year-old and an NFL offensive lineman are dove hunting with the same shotgun and load, the younger shooter is likely to experience more recoil than the lineman because they are smaller and not as strong. A shooter that weighs 300 pounds and has arms the size of a pro bodybuilder can soak up more recoil than your average fourth grader.
Improper gun fit will increase perceived recoil. For instance, if the stock of a shotgun is too short, the shooter may not properly mount the buttstock to their shoulder. The gap between the stock and shoulder will cause the shooter to feel more recoil than if the stock were snugly fit to the shoulder. Too much cast in a stock will result in face slap, causing the gun to recoil into your cheek rather than the stock sliding along it and straight back into your shoulder.
Hit the Brakes on Recoil
Gas-operated semi-automatic shotguns can decrease perceived recoil (free recoil stays the same) because they don’t typically cycle as fast as an inertia-driven auto-loader. This spaces the recoil out so you feel the stock push against your shoulder as opposed to the kick you often receive from an inertia gun, pump, or break-action. Rubber recoil pads are a fine option, too. When the pad compresses, it spaces out the recoil. There are aftermarket stocks with interior springs and pneumatic tubes that also help tame recoil.
Some veteran shooters claim barrel porting, overboring, and lengthening the forcing cone of a shotgun will mitigate recoil, but I have never experienced a noticeable difference. And, it doesn’t make sense that an overbored barrel would mean less recoil. Enlarging the diameter of the bore reduces friction and makes the shot travel faster. The added muzzle velocity would generate more recoil.
Suppressors are becoming increasingly popular on semi-automatic shotguns because they reduce the noise of a gunshot. They combat hunter and gun dog hearing loss, and make life more tolerable for non-hunters who live close to duck clubs, pheasant fields, and shooting ranges. Suppressors also lessen recoil. Instead of forcing all the gas from the propellant out of the muzzle of the gun, which causes more felt recoil, a suppressor disperses the gas to the sides and rearward. They also add weight to the gun, which impacts free recoil.
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