Prior to the release of The Encyclopedia in late 1959, there was no comprehensive service manual available for all American-made firearms, leaving gunsmiths, dealers and hobbyists without a centralized resource. Any information that could be found required significant effort to obtain and was often insufficient. As the firearms detailed in The Encyclopedia age, the information it provides becomes increasingly valuable. Other available resources have long been out of print and original manuals have been lost. Without The Encyclopedia, modern gunsmiths might have to decline repair or restoration work on cherished firearms. The Encyclopedia addresses hundreds, if not thousands, of questions and issues.

• Comprehensive firearm manuals provided by manufacturers detail assembly and disassembly procedures, complemented by extensive gunsmith guides from Winchester, Remington and Browning as of late 1959
• Technical schematics from the manufacturers' archives detail the operational mechanisms of various firearms
• Comprehensive measurements in tabular format for the numerous pins, screws and helical springs are provided in all parts lists