The 35th Edition Blue Book of Gun Values This edition includes 2512 pages all gun values have been thoroughly updated for both modern and antique firearms and it also includes new domestic and imported 2014 makes and models. Other features include the 80-page color Photo Percentage Grading System (PPGS) to help accurately determine the condition of firearms and serialization and proofmark sections to help in identifying firearms. The Blue Book of Gun Values is the firearm industry’s most trusted reference book.