Editing Accurizing (section)

==Determining accuracy==
Determining accuracy is not always a straightforward task, as it depends on a large number of variables.<ref name=beers>{{cite web |url=http://www.chuckhawks.com/accuracy_gun_cartridge_shooter.htm |title=Accuracy: Gun, Cartridge, and Shooter |author =Bob Beers |publisher=Chuck Hawks |accessdate=2007-09-04| archiveurl= https://web.archive.org/web/20070929103158/http://www.chuckhawks.com/accuracy_gun_cartridge_shooter.htm| archivedate= 29 September 2007 | url-status= live}}</ref>

===Factors affecting accuracy===
The accuracy of a shot relies on many different factors, which can be broken down into three broad categories: the firearm, the cartridge, and the shooter.<ref name=beers /> Accurizing generally refers to the processes that are applied to the firearm. Techniques relating to producing accurate ammunition are covered in [[internal ballistics|internal]] and [[external ballistics]], and [[handloading]], and just like accurizing a firearm, the goal is to produce the most consistent possible results. The shooter must also be consistent, and this means that the fundamentals of [[marksmanship]] have to be followed rigorously; any failure on the part of the shooter to remain focused and consistent can result in a bad shot.<ref name=beers /> It's common to use a benchrest or a vise when evaluating ammunition or a weapon for accuracy to eliminate human error.

===Measurements===
[[File:MOA and mrad comparison.png|thumb|right|Comparison of [[milliradian]] (mil) and [[minute of arc]] (moa).]]
Since adjusting the point of impact to match the point of aim is relatively simple with any type of adjustable sights, the primary goal of accurizing is to increase the precision of the firearm, which is generally measured by looking at the dispersion of a number of shots fired at the same point of aim. An ideal group would be one where all shots land in a hole no larger than the diameter of a single bullet; this would indicate zero dispersion. The most common way of measuring groups then is to measure the edge to edge distance of the farthest holes, and subtract the bullet diameter, which gives the ''center to center'' or ''c-c'' measurement of the group. This can be expressed in linear measures (''a 30 mm group at 100 m'', or ''a one inch group at 100 yards'') or in angular measures (''a [[milliradian]]'' or ''[[Minute of arc#Firearms|MOA]] group''). Groups for rifles are traditionally shot at either 100 meters or {{convert|100|yd}}. At 100&nbsp;yd a minute of arc equals {{convert|1.047|in}}, and the one MOA group (approximately 1/3 or 0.3 mil) is a traditional [[Benchmarking|benchmark]] of accuracy. Handguns are generally used at closer ranges, and are tested for accuracy at their intended range of use. Also of importance is the number of shots fired. Statistical likelihood says the fewer shots that are fired, the smaller the dispersion will be.<ref name=groupsize>{{cite web|url=http://www.snipercountry.com/compendium/Comp_G.htm |title=G |accessdate=2007-09-06 |archiveurl=https://web.archive.org/web/20071006141201/http://www.snipercountry.com/compendium/Comp_G.htm |archivedate=6 October 2007 |url-status=dead }}</ref> 3 or 5-shot groups are acceptable for zeroing the sights and rough accuracy estimates, but most shooters{{who|date=August 2018}} consider 10-shot groups to be the minimum for accuracy comparisons.

===Defining accuracy===
[[File:AmmoTestResults.png|thumb|right|200px|Graph showing the results of an accuracy test using 3 different revolvers and 7 different brands of ammunition.]]
Even defining accuracy can be problematic. An example of this can be shown by the following tests, run by ''Performance Shooter'' magazine in December, 1996. The magazine was testing seven brands of [[.38 Special]] [[wadcutter]] rounds in three different [[revolver]]s, a [[Smith & Wesson Model 686]] and Model 52, and a [[Colt Python]] Target model, with six, five and eight inch long barrels, respectively. Ten groups of five shots were fired and measured from each revolver with each ammunition. Click on the image at right to see a larger view of the graph of average group sizes for each type of ammunition and each revolver. The average group size for the overall test was {{convert|2.85|in|order=flip}}.<ref name=ammunitiontest>{{cite web |url=http://www.gun-tests.com/performance/dec96specialammunition.html |title=Performance Shooter .38 Special wadcutter tests |accessdate=2007-08-30}}</ref>

Based on [[average]] group size, the winner was the Model 686, which shot an average group of {{convert|2.69|in|order=flip}} across the brands of ammunition, with a standard deviation between ammunition types of {{convert|0.54|in|order=flip}}. However, the Model 52, while shooting slightly larger groups at {{convert|2.88|in|order=flip}}, was far more consistent across the brands, with a [[standard deviation]] of only {{convert|0.30|in|order=flip}}, and was the most consistent performer of the test. However, if the ammunition was tuned to the gun, the clear winner was the Python, which averaged just {{convert|1.69|in|order=flip}} with its favored brand of ammunition. The Python was also by far the pickiest, however, turning in the largest groups at {{convert|6.08|and|4.0|in|order=flip}} averages with its least favorite brands, for a standard deviation of {{convert|1.6|in|order=flip}}.

Based on this test, answering the question "Which is the most accurate?" becomes a matter of opinion. The 686 shot the best average groups.{{clarify|reason=what does this mean?|date=August 2018}} However, as the Python showed the best performance with one brand of ammunition, it might be the best choice if that brand of ammunition were acceptable for the application in question. If a consistent supply of ammunition were a problem, then the 52 might be the best choice, since it showed the least sensitivity to differences in ammunition.

===Testing methodology===
As the goal of accurizing a firearm is to improve its accuracy, the way accuracy is measured becomes important. A firearm used primarily as a [[hunting weapon]] will need to be accurate on the first shot from a cold, clean barrel, while one used for target shooting may be allowed fouling shots before the first shot for record is fired. Issues of portability or restrictions of certain competitions may limit the alterations that can be made. In addition, every firearm is different, and processes that yield good results on one may not affect another.<ref name=affordable>{{cite web |url=http://www.chuckhawks.com/affordable_accuracy.htm |title=Affordable Accuracy |author =Bill Johnson |publisher=Chuck Hawks |accessdate=2007-09-04| archiveurl= https://web.archive.org/web/20070929102647/http://www.chuckhawks.com/affordable_accuracy.htm| archivedate= 29 September 2007 | url-status= live}}</ref>

Another issue in measuring accuracy is the method by which the gun is secured for the test. The most accurate shooting position is a supported position, such as firing from a benchrest with the firearm well-supported by a shooting rest or sandbags; this eliminates much of the shooter's potential for error and will generally result in much smaller groups than firing from an unsupported position. Even for a firearm that is going to be shot offhand, accuracy testing from a [[Benchrest shooting#Rests|machine rest]] will provide an idea of the ultimate attainable accuracy.<ref name=bullseye /><ref name=unsupported>{{cite web |url=http://www.chuckhawks.com/shooting_unsupported_positions.htm |title=Practical Accuracy in the Field: Shooting from Unsupported Positions |author =Chuck Hawks |accessdate=2007-09-06| archiveurl= https://web.archive.org/web/20070929102838/http://www.chuckhawks.com/shooting_unsupported_positions.htm| archivedate= 29 September 2007 | url-status= live}}</ref>