L. R. Moore III is the founder of Range Master Books, LLC, and a retired Master Sergeant of the United States Marine Corps. With over 20 years of active-duty service, he earned the distinguished title of Range Master by order of NASMFINST 8372.1 and was awarded nine consecutive Expert Shooter awards for both rifle and pistol. His extensive experience as a firearms instructor has equipped him with the knowledge and skills necessary to train shooters of all levels in marksmanship and firearm safety.

Moore created Range Master Books, LLC to provide clear, easy-to-understand training materials that help shooters refine their techniques and develop a strong foundation in firearm safety. His signature book, the Marksman Shooting Ledger, was designed to give shooters a structured approach to improving their accuracy using the BRASS technique—Breath, Relax, Aim, Slack, Squeeze. Passionate about responsible firearm ownership, Moore continues to share his expertise through educational presentations and written resources, ensuring that every shooter has access to the tools needed for success.