Shotgun Slugs Explained: Foster, Brenneke and Sabot

A shotgun slug is a single projectile fired from a shotgun, as SAAMI defines the term. That is the key difference from buckshot, which uses multiple spherical pellets in one shotshell. For most shooters, the big choices are Foster or rifled slugs for smoothbore barrels, Brenneke slugs with their attached wad design, and sabot slugs for rifled shotgun barrels.

Slugs versus buckshot

SAAMI defines shot as spherical pellets used in shotshells. Federal’s buckshot chart lists common buckshot diameters from No. 4 buck at .24 inch to 000 buck at .36 inch.

A slug is different because it is one projectile. That makes slug selection more like choosing a single bullet load than choosing a pellet size. If you are comparing pellet sizes, see our buckshot sizes guide. If you are trying to understand muzzle constriction, see our shotgun chokes guide.

SAAMI also defines a shotgun as a shoulder fired smooth bore firearm designed to fire cartridges containing numerous pellets or a single slug. SAAMI notes that some shotgun bores or choke tubes are rifled for slugs, which is why barrel type matters when choosing slug ammunition.

Foster or rifled slugs

Federal describes a rifled or “Foster” slug as having helix ribbing and a hollow point. Federal recommends the rifled slug for smoothbore shotgun barrels.

The word “rifled” in “rifled slug” can confuse new shooters. In the manufacturer guidance above, this slug type is recommended for a smoothbore shotgun barrel, not a rifled barrel. Always follow the exact ammunition box and firearm manual for the load you are using.

Published Foster slug examples

Published specifications for 12 gauge rifled slug loads can include slug weight, projectile style and muzzle velocity.

Brenneke slugs

Brenneke slugs are their own well known slug family. Brenneke’s 2024 hunting catalog says Wilhelm Brenneke introduced the first Original Brenneke slug in 1898.

Brenneke USA says its slugs use a wad that remains fastened. The company describes a felt wad in Original Classic slugs and a BET plastic wad column in other Brenneke slugs, with the wad secured to the slug and remaining fastened throughout penetration.

Brenneke USA also describes ribs on most of its slugs. In its FAQ, Brenneke says those ribs allow most Brenneke slugs to be used with any choke, while also naming important exceptions for rifled barrel only designs.

Brenneke barrel and choke notes

Brenneke USA says most of its slugs can be used in either smoothbore or rifled barrels. Brenneke names Gold Magnum, Magnum Crush and all brass Super Sabot as exceptions.

Brenneke USA says Gold Magnum, Magnum Crush and all brass Super Sabot are designed only for full rifled barrels and must not be fired from any type of choked barrel.

Brenneke USA also says improved cylinder may give somewhat better accuracy with its ribbed slugs.

Published Brenneke example

Brenneke slug specifications can vary by load.

Sabot slugs

SAAMI defines a sabot as a carrier for firing a sub caliber projectile in a larger bore firearm. SAAMI says the sabot seals and centers the projectile and usually separates after the projectile exits the barrel.

Federal describes a sabot slug as a lead or copper bullet enclosed in a polyethylene sleeve that grips the rifling for spin and accuracy. Federal says sabot slugs should only be used in rifled barrels.

Hornady gives even narrower guidance for its SST Shotgun Slugs. Hornady says SST Shotgun Slugs are designed for fully rifled barrels only.

Published sabot slug examples

This example shows one published 12 gauge sabot slug listing.

Hornady SST Shotgun Slug. Hornady says fully rifled barrels only. Published 12 gauge example: 2 3/4 inch, 300 grain SST, 2,000 fps muzzle velocity.

Hornady’s catalog also lists a 20 gauge SST Shotgun Slug with a 250 grain projectile. Hornady says its 12 gauge and 20 gauge SST Shotgun Slugs deliver sub 2 inch groups at 100 yards and advertise 200 yard accuracy.

Smoothbore, rifled barrels and chokes

The basic pairing from the manufacturer guidance in this guide is simple: Federal recommends Foster or rifled slugs for smoothbore barrels, while Federal and Hornady direct sabot slugs to rifled barrels. Brenneke’s FAQ gives broader compatibility for most Brenneke slugs, with specific exceptions.

SAAMI defines choke as an interior constriction at or near the muzzle end of a shotgun barrel bore. SAAMI also says there are no standards for choke dimensions, so manufacturers may vary choke configurations.

That matters because a choke name alone does not give a complete safety answer for every slug and every shotgun. SAAMI says rifled choke tubes exist for slugs, but SAAMI has no standard for those products and recommends that consumers contact the slug load or choke manufacturer for specific recommendations.

Here is the safest way to read the compatibility guidance:

• For Foster or rifled slugs, Federal recommends them for smoothbore shotgun barrels.
• For sabot slugs, Federal says they should only be used in rifled barrels, and Hornady says SST Shotgun Slugs are for fully rifled barrels only.
• For most Brenneke slugs, Brenneke USA says they can be used in either smoothbore or rifled barrels and says ribs on most Brenneke slugs allow use with any choke.
• For Brenneke Gold Magnum, Magnum Crush and all brass Super Sabot, Brenneke USA says they are designed only for full rifled barrels and must not be fired from any type of choked barrel.

Typical slug weights and what the numbers mean

Published slug weights vary by slug family and load. The examples in this guide include Hornady 12 gauge SST at 300 grains and Hornady 20 gauge SST at 250 grains.

Velocity also varies by load. Hornady lists the 12 gauge SST at 2,000 fps.

Safety checks before buying or firing slugs

Federal warns that shotgun gauges and shells should match, and that failing to properly match ammunition to the firearm can damage the firearm or injure the shooter.

Before using any slug load, check all of the following:

• The gauge marked on the shotgun and the gauge on the ammunition box.
• The shell length marked on the ammunition box and the firearm manufacturer’s instructions.
• Whether the barrel is smoothbore, fully rifled or equipped with a rifled choke tube.
• The exact choke installed, if the shotgun uses interchangeable choke tubes.
• The ammunition manufacturer’s barrel and choke instructions for that exact slug load.

For choke questions, do not rely only on a generic choke name. SAAMI says choke dimensions are not standardized and recommends contacting the slug load or choke manufacturer for specific recommendations, especially where rifled choke tubes are involved.