Military is scattered with ill conceived guns
Reising Submachine Gun on Bougainville, Koiari Raid, 29 November 1943
The Reising went into combat with the Marines on Guadalcanal in August of 1942, one of the first major actions of the Pacific Theater of World War II. The Reising proved unsatisfactory for use in combat and was quickly scorned by the Marines who exchanged their Reising for anything else they could obtain. [The photo to the left was taken on the beach at Bougainville (Koiari Raid, 29 November 1943). The Marine closest to the camera has a Model 55 Reising.]
The Reising symptom was jamming, deadly in combat, but the problem was likely its overly complicated mechanism reacting badly to the salt air and sand of the island campaigns. It was also subject to parts that were not interchangable between weapons, unacceptable in the military system of maintenance and supply.
The Ross Rifle
In trench conditions, surrounded by mud and filth, and when it was essential to have a reliable weapon, the Ross was definitely out of place. It had a long barrel and was difficult to use in the trench's confined spaces, and it frequently jammed. It was indeed a fine weapon - on a firing range under controlled conditions. But the First Division's stand at Ypres in the face of a gas attack, Canadian soldiers threw away their Ross rifles in despair and frustration, and picked up Lee-Enfields from dead British soldiers on the battlefield.
Just to name a few