How Physics affects rifle shooting
http://www.articlesbase.com/education-articles/how-physics-affects-rifle-shooting-1623110.html
Rifle Recoil
http://www.chuckhawks.com/rifle_recoil.htm
Recoil Calculator
http://www.handloads.com/calc/recoil.asp
Ballistic Calculator
http://www.handloads.com/calc/index.html
Rifle Bullet Trajectories
http://www.worsleyschool.net/science/files/bullet/trajectory.html
The National Shooting Sports Foundation youtube site
http://www.youtube.com/user/TheNSSF
Sam Hokin's personal website
http://www.bsharp.org/physics/recoil
Physics 103 text book
Giancoli sixth edition
All images have been linked to the source for which they were found.