Speckin begins with a look at the design intent of the Winchester Self-Loader, which is perhaps one of the most important elements of the gun if one wishes to understand them. A gun cannot be appreciated properly without understanding how well it meets its design intent, and this is a large part of why so few people know much about the 1907 today. It is generally seen as being hopelessly underpowered today, and that view has been around for many decades. In fact, as Speckin explains, the whole series of Winchester Self-Loaders were designed as smokeless semiautomatic analogs for the saddle carbine role. The .351 WSL cartridge is a up-powered stand-in for the .44-40 or .45 Colt, throwing a 180 grain bullet (softpoint or FMJ) at 1900 fps. The 1907 is designed with a short barrel, and completely flat sides to allow easy scabbard carry (that’s why the bolt is operated by a plunger under the barrel; to keep the sides of the gun smooth and unencumbered). It has some weight to it, but that weight is well distributed, and the gun balances well and swings easily. This was not a semiauto replacement for a .30-06 Springfield, it was the gun that filled the space between the Winchester 1892 lever action and the M1 Carbine.
The misconceptions and near total disdain on the part of profession gun writers for the Winchester 1907 are the subject of the next section of Speckin’s book. He references an extensive library of vintage hunting and shooting books and magazines to see what the historical view of the gun has been (and the results are not flattering). Why did all those writers overlook or unfairly disregard the 1907? Well, you’ll have to read the book to see.