Today we have a copy of an official US testing report on the Hotchkiss Revolving Cannon (a 37mm / 1.5″ model). The testing was carried out between September 1876 and February 1877 at Sandy Hook in New York the several officers of the Ordnance Board.
In total, 1,136 rounds were fired from the gun with only 5 malfunctions of any kind. One projectile failed to explode on impact, which was found be to the result of a broken firing in in the fuse. The other four malfunctions were light strikes early in the testing – the firing pin spring in the cannon was found to be faulty and replaced. After that repair, no more problems were recorded. That is an impressive performance for a repeating cannon in 1876, and the Ordnance officers were rightfully impressed. They were also impressed with the manufacturing quality and mechanical design of the gun – particularly how the barrels are set in place and not rotating while loading and firing occurs (unlike the Gattling gun and other contemporaries).
Accuracy and projectile effectiveness were also found to be excellent. The report includes translated excerpts from French and Brazilian tests of the Hotchkiss conducted in 1875, and these reports are similarly glowing. The French testing included a firing sequence at a simulated artillery battalion 1800-2000 yards distant with both a Hotchkiss Revolving Cannon and a pair of .45 caliber Gattling guns. The Hotchkiss made 70% hits, compared to 11% and 3% for the two Gattlings.
You can download the complete report from the Hotchkiss Revolving Cannon page in the Vault, or right here: