Many books on the topic will be under the subject heading Gun Control or its narrower terms. Some subject headings that may be useful include:
The main collection of the library has a variety of books that may pertain to gun control. Try looking at some of these books, and related titles:
Gun control in the United States : a reference handbook
Author: Gregg Lee Carter
Published: 2006
ISBN: 1851097600
Call number: HV7436 .C36 2006
Gunfight : the battle over the right to bear arms in America
Author: Adam Winkler
PublishedL 2011
ISBN: 0393077411
Call number: KF3941 .W56 2011
Gun control
Editor: Lauri S. Friedman
Published: 2009
ISBN: 073774264X
Call number: HV7436 .G8634 2009
The gun control debate : you decide
Editor: Lee Nisbet
Published: 2001
ISBN: 1573928615
Call number: HV7436 .G866 2001
Guns and violence : the English experience
Author: Joyce Lee Malcolm
Published: 2002
ISBN: 0674007530
Call number: HV7439.G72 E546 2002
Can gun control work?
Author: James B. Jacobs
Published: 2002
ISBN: 0195145623
Call number: HV7436 .J3 2002
Firearms control: a study of armed crime and firearms control in England and Wales.
Author: Colin Greenwood
Published: 1972
ISBN: 0710074352
Call number: HV8059 .G77