The image of a shotgun slug has evolved over the years since these frighteningly powerful projectiles first hit the shooting stage in the bygone days of black powder.
The question of whether you can shoot a slug through the barrel of a shotgun equipped with a modified cylinder choke is a popular one among shooting enthusiasts.
The short answer is yes you can, but you want to make sure it’s not just a one-time shot with resulting damage to you, and your shotgun.
Commercially made slugs are designed to shoot through everything aside from a full choke. They’re available in .410, 16, and 20 gauge sizes, but the 12 gauge slug remains the most popular on the market.
Can You Shoot Slugs Through a Modified Choke?
Slugs have been around a long time, since the days of the smoothbore musket. In theory, a shotgun slug was originally almost the same thing as a smoothbore musket slug.
Big, round, and erratic in flight, these heavyweight slugs packed a punch but didn’t fly very fast. The effective accuracy of traditional ball-type slugs wasn’t something you wanted to test beyond a few dozen yards.
When people ask if you can shoot slugs through a modified choke, the answer is yes. But there are other details to consider since all slugs are not the same.
Best Slugs For a Modified Choke?
Slugs took a big step in the late 19th century with the advent of the Brenneke slug designed by German inventor Wilhelm Brenneke and released to the world in 1898. Brenneke slugs shoot well through a modified cylinder since their design creates a slightly smaller diameter slug.
Brenneke began producing these slugs with the idea that rifling on the slug would improve flight just as the rifling inside a rifle barrel improves accuracy by spinning a bullet, allowing it to fly straight through the air.
That didn’t happen. The spiraled grooves cut into the slug didn’t improve accuracy in flight at all. The grooves did swell as the slug flew down the barrel, creating a tighter seal and improving performance.
With a modified cylinder, or something larger, the Brenneke became a very popular way of hunting big game with a shotgun.
An advantage of the Brenneke that keeps it on the market today is that it doesn’t deform as heavily as other lead slugs. This makes it popular for law enforcement and military applications. It is still a popular slug for use in defense against large predators such as grizzly bears.
The Brenneke slug has a wad attached to the lead slug. The wad was originally felt but can be plastic or other materials in modern applications. The wadding remains attached to the shell after it’s been fired.
The Foster Slug
The Great Depression of the 1930s brought a big increase in hunting, particularly large game like whitetail and mule deer. Karl Foster began milling slugs by hand for his neighbors to improve accuracy in hunting big game.
Since many hunters didn’t have the option of changing chokes at this time, and the modified cylinder was the most popular choke size, the Foster slug was a logical choice. It fits nicely through the tighter modified choke and retains its accuracy in the process.
Foster took a cylindrical lead projectile rather than a round ball and carved spiral grooves along the sides. He worked under the same misconception initially that Brenneke had four decades before in Germany that the grooves improved flight trajectory.
While the pattern on the slug didn’t help with accuracy, the weight distribution did. Foster slugs have a conical hole carved out of the rear of the slug. This changes the balance of the slug, making them front heavy.
The idea behind this is similar to a badminton shuttlecock. The weight forward keeps the projectile flying straight. The conical section at the back of the slug can absorb more force, creating a slightly faster speed down the barrel.
The wad behind the slug doesn’t stay with it in flight as the Brenneke slug does, instead, it falls to the ground just as the wad on a field or waterfowl load packed with pellets does.
They sound French, but it’s the design, not the name that makes this slug the most popular among modern hunters. The Sabot with its plastic housing is the safest of the three slug designs to shoot through a modified cylinder, it’s also the most accurate.
A sabot design works well with a rifled choke tube, creating a slug with tremendous range. Some advocates claim accuracy to 200 yards with a 12 gauge sabot fired out of a modified, or larger choke.
They are still not recommended for full chokes.
Sabots have been used on everything from “accelerator” style large game rifles to tank rounds. The concept is to make the round fit the barrel while firing a smaller diameter bullet.
The extra powder sends the slug or bullet down the barrel faster while propelling a smaller-weight bullet or slug. Speed times weight equates to power, and the sabot creates a powerful slug.
In essence, a 12-gauge sabot round is equivalent to a .72 caliber bullet. The 20-gauge is slightly smaller at .61 caliber.
Sabots are more accurate as well. The plastic wad of a sabot round stays with the slug. It works well with modified and improved cylinders but is best with a rifled choke tube at the end of the barrel.
Will Shooting Slugs Through a Modified Choke Harm the Barrel?
Commercially manufactured slugs are safe through a modified cylinder and will not damage the barrel. The same can’t be said of custom-designed slugs that don’t meet the rigorous standards of industrial ammunition companies.
A look online reveals a lot of bad information, that can be dangerous, or potentially deadly. If you read a claim that you can shoot any size slug down any size choke because the shotgun is made of steel, and the slug is made of lead, don’t believe it.
Lead is much softer than steel, but so is mud. What would happen if your shotgun barrel was plugged with mud and you fired off a round? The answer is the barrel will explode, peel back like a banana and possibly blow the firing mechanism up just inches from your face.
Not a good scenario.
Even if a slug can fire through a full choke without damaging it, the ballistics will be so poor that the slug may fly erratically out of the barrel.
Use slugs designed specifically for the type of choke you have on your shotgun. Manufacturers have this information on most boxes of shells and if not, it is on their website.
Why Shoot Slugs Through a Modified Choke?
Slugs are a valuable hunting tool. They have a long, established history as a deer round. In many areas of the country where rifle hunting is limited or outright prohibited, a shotgun loaded with slugs can still give you all the power you need for a successful legal hunt.
Shooting through a modified choke provides a little tighter exit point than larger bore chokes, and will increase accuracy with specific slug designs. The rifled choke is still your best bet, but the modified cylinder with a Sabot slug is amazingly accurate.
The 12-gauge is the most popular round with its huge equivalency to a .72 caliber bullet. A 12-gauge, 16-gauge, or even the much smaller .410 offers great shooting power in a smoothbore setting. Shooting through a modified cylinder will not be a problem with standardized, commercial ammunition.
If you choose to mold your own slugs and load them into shotgun shell casings with higher-powered powder, be careful.
Sliding a slug down the barrel of your shotgun with the modified cylinder choke in place is one way to test, but the speed of a slug roaring down the barrel after it is fired is much different than simply dropping one down the barrel.
Slugs expand with the heat generated as they’re fired, don’t risk it with a fit that is so tight the slug barely fits through the modified cylinder.