Hit Probability of selected 12 gauge buckshot cartridges
as a function of distance from the weapon
25 July 2011
Introduction
The 12 gauge shotgun is a very effective self-defense tool for shooting events occurring at close range.
This particular type of firearm is characterized by propelling several projectiles with each trigger pull, as
compared to the single bullet per trigger pull that is typical of handguns and rifles. Multiple projectiles create
the possibility of hitting and disabling a target on a shot with less-than-perfect shot placement which is
common at night, with a moving target or when the shooter has limited training with firearms.
The shot pellets that comprise buckshot are typically lead spheres with diameters ranging from 0.24”
to 0.36” diameter. Upon firing, the spheres begin to spread out from one another and will continue to do so
for the duration of their travel. This creates the “pattern” from a shotgun. It is this pattern that is addressed
in this report, in an attempt to quantify the hit probability that can be expected from a given shotgun shell
(fired out of a single test shotgun) and to illustrate the benefits of sighting in a shotgun to fire a particular shot
cartridge. Additionally, the practice of utilizing only one particular load of shotshell (and the effects of the
change in center of aim/center of impact if some other load is used) is also addressed.
All of the cartridges were fired from a Benelli m4 shotgun, serial number Y018606. The Benelli m4 is a
semi-automatic 12 gauge shotgun, with a Modified choke installed for the duration of the testing. This
particular weapon was previously sighted in at 25 yards using a Federal Cartridge #4 buckshot load and the
supplied iron sights. To provide a more consistent point of aim, a Bushnell Holo-Sight, serial number 240568,
was carefully installed on the M1913 rails (while the weapon was mounted in a weapon cradle) such that the
iron sight point of aim closely corresponded to the red dot point of aim. At round number 27 an internal
mirror detached from the recoil, breaking the Bushnell Holo-Sight beyond repair. An Aimpoint Micro T-1,
serial number W2423364, was installed in its place (using the iron sight POA as a reference) and used
successfully for the duration of the testing.
Targets were the NRA B-27 silhouette target, positioned at 25 yards and 50 yards distance from the
muzzle. The point of aim on all shots was the ‘X’ symbol present at the center of mass of the target.
Six types of ammunition were tested: Federal Tactical 12 Gauge 2 ¾” 00 buckshot (9 pellet); Federal
Premium 12 Gauge 3” magnum #1 buckshot (24 pellet); Remington Express 12 Gauge 2 ¾” magnum 00
buckshot (12 pellet); Remington Express 12 Gauge 2 ¾” #4 buckshot (27 pellet); Winchester Supreme Double X
Magnum Ammunition 12 Gauge 3" Buffered 000 Copper Plated Buckshot (10 pellet); Winchester Super-X
Magnum Ammunition 12 Gauge 3" Buffered #1 Buckshot (24 pellet).
Figure 1. The threat weapon system
Pictured in Figure 1 is the skeletal and circulatory system of the human body. While there is the
possibility that a single shotgun pellet can disable an arm or leg, we focus only on the torso (as oriented above
and depicted by the B-27 target) for this report as this is the target area that most people have been trained to
aim at.
Shots were physically taken to 50 yards distance, which some may consider to be an excessive amount
for the loosely-constricted choke being used. It must be said, however, that one cannot pick the time and
place of their self-defense shooting, nor the range involved. Shotguns are dominant at closer ranges, but all
effort must be made not to limit ones shotgun shooting to rock-throwing distances only.
It is assumed that a sphere striking the torso does so in a random, uniform distribution and as such can
be considered an effective hit because deflection off of bones could lead a non-vital shot to becoming a fatal
hit. The metric of success for a given load is determined as being a hit probability higher than 0.50 – that is,
some factor of the firearm and cartridge interaction led to a more dense hit pattern than would have been
produced by sheer ‘luck’.
Figure 2. Side-by-side comparison of centers of impact on 25-yard and 50-yard targets for cartridges tested
(l) 25-yard, (r) 50-yard targets
Figure 2 shows the center of the groups for all shotshells fired in this test. Note the horizontal shift of the
loads as range increases. This denotes the necessity, if one were to sight in their shotgun for a particular load,
to do so at several distances up to their desired maximum distance.
Figure 3. Federal Tactical 00 buckshot (2 ¾”) Hit Percentage at 25 yards
Federal Tactical 00 buckshot 2 ¾”
Pellet Hit Percentage
(Adult Male torso at 25 yards)
100
95
Hit Percentage
90
(% pellets on target)
85
80
Nominal
Sighted-In
1
2
3
4
5
Shot Number
Figure 4. Federal Tactical 00 buckshot (2 ¾”) Hit Percentage at 50 yards
Federal Tactical 00 buckshot 2 ¾”
Pellet Hit Percentage
(Adult Male torso at 50 yards)
100
Hit Percentage
(% pellets on target)
50
Nominal
0
Sighted-In
1
2
3
4
5
Shot Number
Figure 5. Federal Tactical 00 buckshot (2 ¾”) Hit Probability as a function of range
h50
Federal Tactical 00 buckshot 2 ¾”
(Adult Male torso at 50 yards)
100
90
Hit Probability
(%)
80
Nominal
70
Sighted-In
60
Measured/ext
50
0
20
40
60
Range
(yards)
80
100
120
Figure 6. Remington 00 magnum buckshot (2 ¾”) Hit Percentage at 25 yards
Remington 00 buckshot 2 ¾” magnum
Pellet Hit Percentage
(Adult Male torso at 25 yards)
100
80
Hit Percentage
(% pellets on target)
60
40
Nominal
20
Sighted-In
0
1
2
3
4
5
Shot Number
Figure 7. Remington 00 magnum buckshot (2 ¾”) Hit Percentage at 50 yards
Remington 00 buckshot 2 ¾” magnum
Pellet Hit Percentage
(Adult Male torso at 50 yards)
50
40
30
Hit Percentage
(% pellets on target) 20
Nominal
10
Sighted-In
0
1
2
3
4
5
Shot Number
Figure 8. Remington 00 magnum buckshot (2 ¾”) Hit Probability as a function of range
h50
Remington 00 buckshot 2 ¾” magnum
(Adult Male torso at 50 yards)
100
80
Hit Probability
(%)
60
Nominal
40
Sighted-In
20
Measured/ext
0
0
10
20
30
Range
(yards)
40
50
Figure 9. Remington #4 buckshot (2 ¾”) Hit Percentage at 25 yards
Remington #4 buckshot 2 ¾” Maximum
Pellet Hit Percentage
(Adult Male torso at 25 yards)
100
95
Hit Percentage
(% pellets on target)
90
Nominal
85
Sighted-In
80
1
2
3
4
5
Shot Number
Figure 10. Remington #4 buckshot (2 ¾”) Hit Percentage at 50 yards
Remington #4 buckshot 2 ¾” Maximum
Pellet Hit Percentage
(Adult Male torso at 50 yards)
60
40
Hit Percentage
(% pellets on target)
20
Nominal
Sighted-In
0
1
2
3
4
5
Shot Number
Figure 11. Remington #4 buckshot (2 ¾”) Hit Probability as a function of range
h50
Remington #4 buckshot 2 ¾”
(Adult Male torso at 50 yards)
100
90
Hit Probability
(%)
80
Nominal
70
Sighted-In
60
Measured/ext
50
0
10
20
30
Range
(yards)
40
50
60
Figure 12. Winchester #1 buckshot (3” magnum) Hit Percentage at 25 yards
Winchester #1 buckshot 3” magnum
Pellet Hit Percentage
(Adult Male torso at 25 yards)
100
80
Hit Percentage
(% pellets on target)
60
40
Nominal
20
Sighted-In
0
1
2
3
4
5
Shot Number
Figure 13. Winchester #1 buckshot (3” magnum) Hit Percentage at 50 yards
Winchester #1 buckshot 3” magnum
Pellet Hit Percentage
(Adult Male torso at 50 yards)
30
25
20
Hit Percentage
15
(% pellets on target)
10
5
0
Nominal
Sighted-In
1
2
3
4
5
Shot Number
Figure 14. Winchester #1 buckshot (3” magnum) Hit Probability as a function of range
h50
Winchester #1 buckshot 3” magnum
(Adult Male torso at 50 yards)
100
80
Hit Probability
(%)
60
Nominal
40
Sighted-In
20
Measured/ext
0
0
10
20
30
Range
(yards)
40
50
Figure 15. Federal #1 buckshot (3” magnum) Hit Percentage at 25 yards
Federal #1 buckshot 3" magnum
Pellet Hit Percentage
(Adult Male torso at 25 yards)
100
80
Hit Percentage
(% pellets on target)
60
40
Nominal
20
Sighted-In
0
1
2
3
4
5
Shot Number
Figure 16. Winchester 000 buckshot (3” magnum) Hit Percentage at 25 yards
Winchester 000 buckshot 3” magnum
Pellet Hit Percentage
(Adult Male torso at 25 yards)
100
Hit Percentage
(% pellets on target)
95
Nominal
90
Sighted-In
85
1
2
Shot Number
3
Conclusion
Hit percentage can vary significantly from cartridge type to cartridge type when fired from the same
weapon. We recommend choosing a shot size based on terminal performance at the realistic maximum range
that your situation presents to you. The spherical shape of a shot pellet does not lend itself to aerodynamic
efficiency, but it has the reverse advantage of rapid deceleration once it hits a fluid medium, which leads to
greater lethality. As such, a pellet that performs optimally at 10ft distance will not perform optimally at 25
yards – it is very likely that the damage at shallow depths and overall penetration will be decreased due to the
decreased kinetic energy at impact (as a result of aerodynamic drag working on the pellets).
Once a desired shot size is found, it is recommended that several different brands and loads containing
this shot size be tried out in your shotgun. Sight in your shotgun for a given load; an appropriate procedure
can be found on www.BrassFetcher.com. Placing the target at your maximum anticipated range, fire several
shots of each cartridge and select your desired load based on the greatest hit percentage of pellets on the
target. This way, your shotgun will be optimized for your maximum expected range of engagement but also
capable of throwing a more dense shot cloud, should you be engaged from a longer-than-anticipated distance.