I don't leave the house without it. I started out knowing very little about collecting military rifles. No idea on value, etc. This book helps tremendously with that. It gives a rough price range of values based on condition and usually also includes the same for the bayonet that goes with them. The vast majority of rifles you will encounter are included in this volume. If you are a general collector, this book is going to work well for you. If you are going to be a more specialized collector, you may want something additional. It does break down Garands by manufacturer for instance but may not include every variation possible, same with German and Japaneserifles. It does go into some detail concerning all matching numbers, whether the mum is present or not, things like that. I have also encountered a few issues of missing rifles. Some I later found in the Mauser section under Germany
when the rifle was for a smaller nation.
It's pros far outweigh the few cons. My general rule of thumb is that I will simply not purchase a rifle if it does not fit within the guidelines of this book unless I know for a fact based on personal knowledge that the rifles are currently going for higher. Something that comes into play more often now because my volume is now 8 years old. I need a new one badly but, I'm still getting guns at these older prices.
It also includes all major handgun, machine gun, etc types as well.