The carbine design was produced beginning in 1833, using a smoothbore barrel of 23 inches in length. It had an overall length of 43 inches, weighed 8 lbs, and was the first caplock firearm adopted by the U.S. Army. The following year, a carbine in .69 caliber was introduced for the Regiment of Dragoons, with a second run in 1836–1837. Barrel length was reduced to 21 inches in 1840, and a "fishtail" breech lever design credited to U.S. Army Captain James Huger was also introduced for the next 7,000 carbines, including the M1842 carbine, the final "regulation design" of the series.