Shotgun slugs

A shotgun slug is a single projectile primarily designed to be fired from a smooth-bored shotgun. Shotgun slug ammunition is available in most of the common shotgun calibres.

The simplest form of slug is a round ball (sometimes referred to in the United States as a pumpkin ball or pumpkin shot). Since it is a symmetrical projectile, it will not significantly deviate from its intended path if it begins to spin due to air pressure. However, a smooth-bored shotgun firing a round ball is essentially a musket with its inherent short range and accuracy problems.

To enhance a slug's performance, both externally and terminally, it requires to be elongated and to have its centre of mass moved forwards. Being elongated, it is also preferable for the missile to be spin stabilized to prevent it from tumbling.

The original Brenneke slug (see Figure 2.10) overcame these problems via the use of a solid lead, pre-rifled projectile with an attached plastic, felt or cellulose fibre wad. The wad provides drag stabilization by moving the centre of mass forwards. The cast rifling has little or no effect in spinning the projectile as it passes through the air.

Another early design was the Foster slug (see Figure 2.11). This was basically a short round- nosed bullet with a deep cup in the base. Foster slugs are also made with rifling-type grooves cast into the outside of the missile. The cupped base also expands on firing producing a seal with the bore.

Whilst it is generally accepted that shotgun slugs do not have to be fired through a cylinder barrel, it is not recommended that full choke barrels be used. This is due to the fact that the pressure required to compress the slug through the choke will eventually flare the end of the barrel thus reducing the degree of choke.

Figure 2.10 Brenneke slug.

Figure 2.11 Foster slug.

Figure 2.12 Sabot slug.

Saboted slugs (Figure 2.12) are sub-calibre missiles which have a discarding plastic collar surrounding the missile to bring it up to standard calibre. They are generally designed to be fired from a special rifled shotgun barrel to spin stabilize the missile. Originally, these were called Paradox weapons and had a short length of rifling at the muzzle end of the barrel. More modern weapons can have rifling at the end of the barrel or along its full length.

Due to the reduced drag and high initial velocity, saboted slugs have significant advantages in external ballistics over a normal shotgun slug. Some saboted slugs use fins or a lightweight plastic portion at the rear of the missile to provide stability from smooth-bores.

The brenneke slug. The Brenneke slug was developed by the German gun and ammunition designer Wilhelm Brenneke (1865-1951) in 1898.

The original Brenneke slug was a solid lead projectile with fins cast onto the outside, much like a modern rifled Foster slug (see Figure 2.10). There was a plastic, felt or cellulose fibre wad screwed to the base that remains attached after firing. This wad serves both as a gas seal and as a form of drag stabilization, much like the mass-forward design of the Foster slug.

The fins or rifling is easily deformed to pass through choked shotgun barrels and do not impart any significant stabilizing spin on the projectile.

Since the Brenneke slug is solid, rather than hollow like the Foster slug, the Brenneke will generally deform less on impact and provide deeper penetration. The sharp shoulder and flat front of the Brenneke mean that its external ballistics restrict it to short-range use as it does not retain its velocity well.

The Brenneke slug is available in a number of normal shotgun calibres, but 12 bore and 0.410" calibre are probably the most popular.

The foster slug. The Foster slug was developed by Karl Foster in 1931. The defining characteristic of a Foster slug is the deep depression in the base, which places the centre of mass very near the tip of the slug, much like a shuttlecock. If the slug begins to tumble in flight, drag will tend to push the slug back into straight flight. This gives the Foster slug stability and allows for accurate shooting out to ranges of about 50-70 yd.

Foster slugs may also have rifling, which consists of 11 or 12 fins either cast or swaged on the outside of the slug. Contrary to popular belief, these fins impart little or no spin to the slug as it travels through the air.

The actual purpose of the fins is to allow the slug to be safely swaged down when fired through a choked shotgun barrel, although accuracy will suffer when such a slug is fired through chokes tighter than improved cylinder. Cylinder choke is the one recommended for best use.

As with all shotgun slugs, it is possible to fire Foster slugs through a Shotgun Slug,1 that is rifled, Barrel. It should be noted, however, that as the slug is not lubricated, leading of the rifled portion of the barrel becomes a great problem necessitating regular cleaning to maintain any degree of accuracy.

The sabot slug. The main characteristic of a sabot slug is the plastic carrier or sabot, which is of bore size or sometimes a little larger to enable the sabot to engage the rifling found in modern slug barrels.

The slugs contained in sabots can be anything up to 0.50" calibre and are usually hollow pointed. Those for police use are usually of a solid hard metal alloy material for barricade penetration or door lock and hinge removal.

Although the sabot slug is used primarily in rifled barrels, some designs of sabot slugs can be fired in smooth-bore shotguns most notably the Brenneke Rubin Sabot, a sub-calibre slug utilizing the familiar Brenneke attached wad system.

The smaller projectile held within sabots will have a much flatter trajectory, and will travel at much higher velocities than the more traditional foster or rifled slug. Saboted slugs will, when fired from a rifled barrel, produce near rifle-type accuracy.

Another advantage of the sabot type of shotgun slug is that no lead comes into contact with the barrel, thus preventing lead fouling.

Penetration of foster and sabot slugs. The following table gives an indication of the penetration potential of shotgun slugs. Penetration figures for normal shot are for comparison purposes (Table 2.4).

It is generally accepted by those involved in the wound ballistics field that a minimum penetration of 12 in. of 10% ordnance gelatin is one of the criteria needed to provide reliable incapacitation of a human assailant.

1 A shotgun with rifling at the muzzle end of the barrel.

Table 2.4 A comparison of shotgun pellet and solid slug penetration in 10% ordinance gelatine.

12-Gauge penetration tests in 10% gelatin

Load

Number of pellets

Penetration at 7 yd

000 Buck

8

14"-16"

00 Buck

9

13"-15"

1 Buck

16

12"-14"

#4 Buck

27

9"—11"

#6 Shot (copper-plated hard shot)

280

4"-6"

1 oz Foster slug

18"

450 g sabot slug

21 "

When used in a police or military situation, shotgun slugs are often used against hard targets.

To illustrate the penetration potential of shotgun slugs, the test was carried out using standard NATO 0.138" steel test plates. Buckshot loads are shown for comparison purposes.

Results are shown in Table 2.5.

The common misconception is that the shotgun slug has an extremely short range as well as a very poor trajectory. This is not quite true, although past 125 yd, the velocity and hence kinetic energy does drop off quite considerably (Table 2.6).

Other types of specialized, single missile, shotgun ammunition include the breaching or Hatton cartridge and tear-gas rounds.

The Hatton round is made specifically for police or military use and is designed for the breaching of doorways (Figure 2.13).

It is typically fired at a range of 4-6 in., aimed between the doorknob and door jamb, destroying the locking mechanism. It can also be used to remove the hinges in a similar way.

The missile is a single 12-bore, frangible slug weighing 770 gr (1.6 oz). The round is made of compressed zinc or lead powder bonded with hard wax. When fired, the full force of the round is delivered to the target, minimizing the risk

Table 2.5 A comparison of shotgun pellet and solid slug penetration against 0.138" NATO steel plate.

12-Bore penetration tests against SAE 1010 0.138" NATO steel plate

Table 2.5 A comparison of shotgun pellet and solid slug penetration against 0.138" NATO steel plate.

12-Bore penetration tests against SAE 1010 0.138" NATO steel plate

Load

7 yd

2 5 yd

000 Buck

N

N

00 Buck

N

N

1 Buck

N

N

4 Buck

N

N

1 oz Foster slug

P

2

450 g sabot slug

P

P

Table 2.6 External ballistics for Foster-Type 12B slug.

Range (yds)

Velocity (ft/sec)

Deviation (ins) from Point of Aim when zero = 75 yards

Deviation (ins) from Point of Aim when zero = 100 yards

0

1440

-1.0

-1.0

25

1320

0.7

1.4

50

1200

1.1

2.5

75

1120

0

2 .1

100

1050

-2.8

0

125

1000

-7.5

-4.0

150

960

-14.4

-10.2

+9 -1

Responses

  • helen
    What are the ballistics for a 8 gauge shotgun slug?
    7 years ago
  • Abrha
    What type of wad for shotgun slug?
    7 years ago
  • karita
    How to zero shotgun for100yds with slugs?
    6 years ago
  • bonnie
    What speed dose shotgun slug ballistics?
    6 years ago
  • aurelia
    What is bullet drop for shotgun rifled slug ballistics?
    6 years ago
  • mauno
    What is bullet coefficient shotgun slugs?
    5 years ago
  • MEZAN
    What is balistic coefficent of shotgun slug?
    5 years ago
  • sebastian
    Can police do ballistics on shot gun shells?
    5 years ago
  • rose
    When will a smooth bore bullet tumble?
    5 years ago
  • temesgen
    How much does a 12 gauge sabot slug drop?
    5 years ago
  • shishay
    What is the kinetic energy of a 1 oz 12 gauge slug?
    4 years ago
  • Dennis
    Are slugs for shotgun higher that 4 shot?
    4 years ago
  • uta moench
    How much drop in trajectory with slug?
    4 years ago
  • jesus aguirre
    What is the trjectory of a 12gauge sabot slug?
    3 years ago
  • einojuhani salama
    What is the kinetic energy of a 12 gauge one ounce luck?
    3 years ago
  • lobelia
    What is the ballistic drop of shotgun rifled slugs?
    3 years ago
  • Gino
    Does 12ga slug rise or drop when shot?
    3 years ago
  • katherine
    Can shotgun ballistics be compared?
    2 years ago
  • hildigrim brandybuck
    Does a automatic shotgun losing any velocity when shooting a rifled slug?
    11 months ago
  • Dafne Zetticci
    Do shotgun slugs tumble in air?
    8 months ago
  • Eliana
    What drag table to use for slug guns?
    8 months ago
  • sointu
    How much energy from 12 ga slug shot from 18inch barrel?
    8 months ago
  • giona
    Does a slug rise when it leaves a shotgun barrel?
    8 months ago
  • Kristian
    Does a bullet using a sabot touch the barrel?
    7 months ago
  • Adaldrida
    How much does a 12 gauge rifled slug weight?
    7 months ago
  • IRENE
    How do i figure time of flight for a shotgun slug?
    7 months ago
  • Mikki
    What does the shotgun shell ballistics table mean?
    7 months ago
  • Cerys
    How much energy does 410 slug produce?
    6 months ago
  • markus
    How much does a 12gauge Slug Gun drop in 25 Yards?
    6 months ago
  • Odetta
    What is the noise level of 12 guage sabot ammunition?
    6 months ago
  • Michelino
    What ballistics would a slug fired from a standard 12 gauge make?
    3 months ago
  • robinia
    How much would a one ounce rifled slug drop in 400 yards?
    3 months ago

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