Shotgun

Licenses:

The shotgun image is edited from http://callofduty.wikia.com/wiki/File:Personal_Rambo362_PMG_M1014_Breaching_shotgun.jpg which is in public domain ('This file has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. This applies worldwide.'). The shotgun sounds are compressed to mp3 from http://soundbible.com/1959-Shotgun-Reload-Pump.html and http://soundbible.com/1958-Shotgun-12ga-Fire.html, both licensed under https://creativecommons.org/licenses/by/3.0/.
The revolver image is edited from http://en.wikipedia.org/wiki/File:Colt_New_Service_1370.jpg, originally sourced from http://www.adamsguns.com/. The silenced gun image is heavily edited from http://en.wikipedia.org/wiki/File:SilencerCo_Osprey_.45.JPG, placed under Creative Commons CC0 1.0 Universal Public Domain Dedication. Revolver cocking sound is edited from http://soundbible.com/1988-Gun-Cocking-Fast.html, licensed under the Attribution 3.0 license. Gun sounds are edited from http://soundbible.com/1855-Gun-Loud.html and http://soundbible.com/930-Gun-Silencer.html, licensed under the Attribution 3.0 license.
The AK-47 image is edited from http://en.wikipedia.org/wiki/AK-47#mediaviewer/File:AK-47_type_II_Part_DM-ST-89-01131.jpg, which has been placed in the public domain. The AK-47 pop clip sound is from http://soundbible.com/1404-Pop-Clip-In.html and the burst sound is from http://soundbible.com/1228-Machine-Gun-Burst-50-Cal.html, both licensed under the Attribution 3.0 license.
The minigun image is edited from http://en.wikipedia.org/wiki/Minigun#mediaviewer/File:DAM134DT.png which is in public domain. The minigun sound is compressed to mp3 from http://soundbible.com/1920-Minigun.html, licensed under the Attribution 3.0 license.