Model made from 1915-1927. Has a 10-round magazine, blue finish, checkered walnut grips and 6.625" barrel. Designed for .22 LR standard velocity ammunition. Rear sight adjustable for windage, front sight for elevation. Up until approximately serial number 31000 the barrel was a very thin, so-called "pencil barrel". Barrel weight and diameter were increased slightly in 1922, to what collectors now call the "medium weight barrel". Also numerous small changes in grips, magazines and markings over the years. Approximately 54,000 were made in all variations.