( Physics Research Project )
~20 Gauge Spread~
By, Ben Andrews
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A 20 gauge shotgun is a weapon used to hunt small birds, rats, and moles. It is one of the smaller models of a shotgun with less of a kick and less weight. The different shot sizes associated with this gun range from size number 3 the larges pellet size shot to the number 9 shot size with the smallest pellet size. There are also three different types of chokes used to control the spread of the pellets when fired at a target, improved has the most spread, modified has the medium spread, and full has the most condensed spread.
I want to find out the change in spread using a 20 Gauge shotgun, and shooting three different shot sizes through the three different types of chokes onto sheets of cardboard.
(Guns & Ammo, GunHunter, Shotgun News, Shotgun Sports, Guns) These are all magazines that are related to the field of shotguns and the sports and equipment used to maintain and assemble shotguns to an owner’s preference.
I believe that the size 4 shot size will have the most spread and the least concentration using the Improved choke compared to the other shot size and choke combinations. I believe this because the Improved choke allows for the maximum spread and the number 4 shot size has the least number of pellets shot so the pellets will be able to bounce around in the barrel more and have an impact on the pellets angel out of the barrel.
· 20 Gauge shotgun
· #4, #6, #9 shot sizes
· IMP, MOD, & FULL choke sizes along with choke remover
· Wooden pallet used as stand for cardboard
· Tape measure
Choke size Range
Improved Moderate Full
#4 185.42 210.82 185.42 25.4
Shot size #6 177.8 182.88 157.48 25.4
#9 233.68 182.88 177.8 55.88
( circumference measurements in cm.)
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In my experiment I am trying to find out the difference in spread with three different shot types 4, 6, & 9, being shot out of three different chokes to find out the different spread patterns. First I set up a wood pallet 17 m away from the shooting line, then I leaned a large sized piece of cardboard up against the pallet and divided it into thirds. Next I shot into the cardboard with the #4 shot in one third, the #6 shot in another third, and the #9 shot in the last third, all of this while using the Improved choke. Next I repeated the last step two more times with different pieces of cardboard, and using the Modified, and the Full chokes. Once all of the shooting was done I marked on the cardboard the outer points of the shown spread from the pellet holes, and then traced a circle around the spread from point to point. Last I gathered my data by measuring the circumference around the spread to determine the shot spread in relationship to the other shot, and choke combinations. The spread density however was mainly determined by visual analysis.
The experimental uncertainty in my opinion is about + or – 4cm. The variables that would have had an affect on the spread such as the barrel of the gun getting too hot and expanding making the spread wider was taken into consideration, so I waited 4 minutes between each shot allowing the gun to cool down. I also used the same type of 20 Gauge shells ( Remington ) with all the different types of shots, and I used the same gun all throughout the experiment. All of these factors were taken into consideration to minimize the chance of error.
In the case of my Experiment ( 20 Gauge spread ) I have found that my hypothesis was incorrect. I believe this to be so because the #9 shot has the most number of pellets and that combination with the Improved choke ( widest spread choke ) allowed the pellets to bounce off one another inside the barrel causing the pellets to exit the barrel in a disorderly fashion and therefore have the most spread. If I was able to do this experiment another way I would do it indoors in a more controlled environment and I would test all of the different shot sizes instead of just choosing three to analyze. This has been one of the most exciting and at the same time one of the most personally informational experiment I have ever done, and it makes me appreciate the time and effort scientists put in to experiments and the useful information used taken form them.
( This shows the spread and the power behind the shot to project the pellets )
( Talks about the different types of shotguns and their differences )
( Shows the different patters and their spread at different distances )
( Explains the shotgun it self, safety, and correct shots to be used )
( Examines the reason for the wad, and what it does for the powder, and the shot )