Changes

<!-- NOTE to Editors: We request that you please DO NOT change or remove ANYTHING in the [[Second Amendment]]-[[Gun rights]]-related Template links preceded with "{{", such as {{Template:Firearms_topics}} or {{Template:Firearms SAMMI glossary quotation}}. Thank you. -->'''Sectional density''' (SD) ''' is a [[Glossary of Firearms and Second Amendment Terms|firearms term]] related to [[ammunition]]. According to [[:Category:Gun Writers|gun writer]] Matthew Boyd, sectional [[density]] is "the [[diameter]] to weight [[ratio]] of a [[bullet]]. Calculated by dividing the bullet's weight in [[pound]]s by its [[diameter]] in inches. Sectional density is important because, all other factors being equal, the higher the SD the better the [[penetration]] of the bullet."<ref> Boyd, Matthew J., "[http://www.chuckhawks.com/ Basic firearms Terminology Defined]."  [[Guns and Shooting Online]] - [[Chuck Hawks]].com, 2012. Accessed February 19, 2015</ref>

<!-- NOTE to Editors: We request that you please DO NOT change or remove ANYTHING in the [[Second Amendment]]-[[Gun rights]]-related Template links preceded with "{{", such as {{Template:Firearms_topics}} or {{Template:Firearms SAMMI glossary quotation}}. Thank you. -->'''Sectional density''' (SD) is a [[Glossary of Firearms and Second Amendment Terms|firearms term]] related to [[ammunition]]. According to [[:Category:Gun Writers|gun writer]] Matthew Boyd, sectional [[density]] is "the [[diameter]] to weight [[ratio]] of a [[bullet]]. Calculated by dividing the bullet's weight in [[pound]]s by its [[diameter]] in inches. Sectional density is important because, all other factors being equal, the higher the SD the better the [[penetration]] of the bullet."<ref> Boyd, Matthew J., "[http://www.chuckhawks.com/ Basic firearms Terminology Defined]."  [[Guns and Shooting Online]] - [[Chuck Hawks]].com, 2012. Accessed February 19, 2015</ref>

==Bibliography - Further Reading==

==Bibliography - Further Reading==