Barrel length 24", 28" or 30" usually octagonal, but part round/part octagonal as well; calibers .32, .38 and .44 rimfire. Markings: "BALL & WILLIAMS/Worcester, Mass.", "BALLARD'S PATENT/Nov. 5, 1861" and "MERWIN & BRAY, AGT'S/ NEW YORK", on facets of barrel until about serial no. 9000. Thereafter, patent name and date on right side of frame and manufacturer and agents on left side of frame. On early production (200 to 1500), extractor knob is smaller and crescent shaped. Early production (prior to about serial no. 10,000) have solid breech-blocks; after that number breech-blocks are made in two halves. A few of these arms were made with bronze frames to facilitate engraving and plating. These should command a higher premium.