First tested in by the U.S. Army in 1881, mountain guns were ideal for rugged terrain, such as that found in the West, due to their lighter weight (362 lbs). Also, they could be broken down into parts to allow transportation of the gun and ammunition on three mules. Due to its use of fixed ammunition, this Hotchkiss gun could fire rapidly.
It fired two types of ammunition; explosive shells with impact fuses, effective to 3500 yards, and canister, for short range. This particular model, made in 1885, is complete, including the rear sight, and was converted to center-fire by Rock Island Arsenal. It includes an extensive file of all historical and technical details.
This Hotchkiss mountain gun was designed between 1876 and 1877, by Benjamin Hotchkiss in response to the U.S. Army’s need for a light, effective alternative to the muzzle-loading mountain artillery of the time. Hotchkiss quickly announced a “quick-firing”, highly-portable cannon in 1.65” caliber (42mm), with self-contained ammunition in both canister and explosive presentations.
A 1878 Ordnance Report from Brigadier-General Steven Vincent Benet, narrates part of the history of this gun, stating:
Early in 1876, Colonel Miles, Fifth Infantry, suggested that a light field-gun weighing less than 500 pounds be provided for service on the plains, to replace the obsolete mountain howitzer. The subject was submitted to the Ordnance Board for consideration, with the remark “that a rifled gun, probably a breech-loader, that can travel with cavalry, and has an effective shell range beyond that of rifled small arms, not less than 1,500 yards, would probably meet the requirements of the service”. While under consideration, Mr. B.B. Hotchkiss presented for examination and trial a light breech-loading rifle that gave promise of efficient service on the frontier, and fulfill(ed) the conditions of mobility, range, and accuracy. One was procured, and issued to the Department of Dakota in 1877, and was used in the field that summer. It weighs 116lbs, and its caliber is 1.65 inches. It uses a charge of 6 ounces of powder, and a percussion shell weighing 2 pounds. While many defects in its mechanism, and in the carriage and ammunition, have been pointed out after the experience of a campaign, showing that modifications are desirable to add to its effectiveness, it did excellent work. I am informed that Colonel Miles expressed himself satisfied that it had rendered efficient service, and was a valuable weapon. With all its defects, others have been called for, and the five now in possession of the department will be issued to the troops.
The 42mm Hotchkiss mountain gun is known to have been used in the Indian Wars and the Battle of Manila, but was declared obsolete in the late 1890’s, at which point it was relegated to use by forces in South America and a few militias.