REFERENCE: Shotgun slugs and chokes

“Is it safe to shoot slugs out of my choked shotgun” seems to be a very common question all over the internet.
Generally speaking the simple answer is “Yes”.
There are though quite a few things to take into consideration if you want to start putting slugs through your trusty ol’ scatter gun.

Is your gun safe to use with modern shotgun shells?
There are many (Probably millions) of shotguns that are well over a 100 years old, they are not safe to fire with any modern ammunition unless the gun has been inspected by a competent shotgun smith and given the thumbs up. There are many beautiful old Damascus scatter guns that have been given that thumbs up and are being used for hunting and sports shooting.

Shotgun slug loads create less pressure that a load of shot of the same weight.
when a bird shot shell is fired the pressure applied to the shot from below causes it to swell outwards and the shot grips the wall of the barrel kind of like brake pads on a car. This effect does not come into play when firing a slug, thus resulting in less pressure weight for weight.

There are many different types, shapes and sizes when it comes to slugs.
Foster Slug
Foster slugs or Rifled slugs are designed to be shot from choked smooth bore barrels. They are basically a front heavy lead thimble with angled grooves cast into the outside (some types of Foster slugs like the Lee Keydrive slugs), they are named after their inventor Karl M. Foster and the fact that they look like a section of rifle barrel turned inside out. The “rifling” is designed to collapse, to squash down evenly as the slug makes its way through the choke.
Foster slugs generally measure around .69 and are loaded into shot cups to bring them up to full bore width. they were designed in 1931 (and later patented in 1947) to enable deer shooting during the Great Depression.
Forster slugs can be shoot through any choke but are best shot with an Open / Cylinder choke or an Improved Cylinder, compressing the slug beyond that can cause it to deform and screw up the accuracy.

A classic Brenneke slug with a felt wad
The Brenneke slug was designed in 1898 by Wilhelm Brenneke.
Brenneke Slugs are rifled like a foster slug but are solid with a wad attached to the base, the light weight wad causes what is called drag stabilisation and also creates the gas seal.
Original Brennekke’s had felt and nitro-card wads, but modern versions may have plastic wads instead. Due to the slugs being solid they are usually heavier than foster slugs, which is a double edged sword on one hand the have greater penetration but this comes with greater recoil.
Brenneke slugs can be shot through any choke but are best shot with an Open / Cylinder choke or an Improved choke, being a solid slug it takes more energy to compress it through a tight choke which means more pressure and greater recoil.

Plumbata Slug
The Plumbata slug is a modern hybrid of the Foster and Brenneke slugs. There are many different models on the market, they are hollow based like a foster but the use a special wad the fills the hollow base and keeps it attached to the slug during flight much like a Brenneke.
The Plumbata wad serves several purposes, it forms the gas seal, it causes Brenneke style drag stabilisation and by filling the base cavity it supports the slug preventing deformation.
Plumbata slugs can be shot through any choke but like their forbears they perform best with a Cylinder or Improved Cylinder choke.

A selection of projectiles loaded into Sabots
Sabot slugs are under sized projectiles (often .50 cal) that are held in a special wad called a sabot that is designed to centre the projectile in the bore and then release the projectile once its free of the barrel.
Sabot slugs are designed for use in rifled barrels which produce the spin that the projectiles need for stability. while they are generally accepted as the most accurate slug design they are no good in a smooth bore shotgun and therefor not suitable for use with chokes.

Round Ball Slugs in various wads
Round Ball slugs as you would guess are simply large lead balls, they vary in size from .69 balls that fit into standard shot cup wads to full bore balls of .73 cal. Round balls depending on their size can be fired from smooth bore or rifled barrels, a choke is not recommended in a smooth bore as the deformation caused can effect accuracy.

Wax slug
the remnants of a fired Cut shell
Improvised Slugs, Waxers, Cut Shells…
Every man and his dog seems to have an opinion on these, good or bad I’ll leave it up to you to decide.
Wax slugs are made by emptying the pellets out of a birdshot load, mixing the shot with melted wax and then pouring it back into the shell where it cools into a solid’ish slug. wax slugs will usually hold together until they hit the target and then the fragment into pieces again. I personally have never made or shot wax slugs so I couldn’t say how they would perform through a choke. Youtube has a heap of videos and their is no definite consensus on Wax slugs.
Cut shells work the same as Wax slugs when the hit the target, but the are made by cutting around the hull of a birdshot shell so that when it is fired the hull separates and the forward half or the hull travels through the barrel with the wad and shot contained inside it.
Once again there is no consensus on the safety of shooting cut shells, the diameter of the hull is larger than the bore and a significant amount of pressure is required to force the whole thing through the bore. I have personally bulged the barrels of a cheap quality double barrel shotgun shooting cut shells, but then I have also shot them through sturdy single shots without a problem. The internet is full of opinions on cut shells and I’m a bit each way on them, I would definitely not shoot them through a choked bore as the are already being choked substantially to fit the barrel.

Above is only a summery of some of the more common slug, there are a multitude of other types that have been used with varying success and accuracy. Many people have strived to gain greater accuracy with smooth bore slug loads, they will never really compete with a rifle when it comes to precision but when you really want to put a bloody big hole in something you can’t beat a 12ga slug!


A thread explaining gauge and choke sizes


So can a rifled barrel shotgun be effectively used with shot?

You can technically, but because the shot column expands in the bore it engages the rifling and picks up spin like a slug would. Once it exits the bore though it spreads like wild fire resulting in huge patterns.
So you could safely shoot them but you’re not likely to effectively hit anything more than a few meters away.

Very well written and informative. There are some nasty looking slugs in those photos.

Does not surprise me in the slightest. This is not what a shotgun is designed for.


100% yet many shoot them without any trouble.
I would love for someone to do actual pressure readings on them.

People only get away with it because companies always build a significant safety margin.

Wax slugs are very good,but you can bugger off with cut shells

I think the shotgun slug gurus should replicate that big hollow point slug that we watched on y tube. I would be very interested in this and happy to join the working party. to create a design and mold.

So can a rifled barrel shotgun be effectively used with shot?

Some pretty expensive ones can, well " Paradox " bore ones anyway =

Any smoothbore can fire slugs. Been doing it for centuries.
The beauty of those paradox guns is there ability to fire a bloody heavy solid at a decent speed without raising pressures too high.

Cbe make molds already. 900gn hollow point

Theres another mob making jacketed full bore slugs in the US too
Can’t order them from Straya but unfortunately!

Nope,not those ones. Ill send you the link

Very cool. Do they ship to Australia?

I think so

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Has anyone that you guys know of experimented with copper plating / electro plating slugs?