During World War II, the Reising first saw action on August 7, 1942, exactly eight months to the day after Pearl Harbor, when 11,000 men from the 1st Marine Division stormed the beaches of Guadalcanal, in the Solomon Islands. The same date of Guadalcanal's invasion, the Model 50 and 55 saw action with the 1st Marine Raiders on the small outlying islands of Tulagi and Tanambogo to the north. Two companies of Marine paratroopers also used Model 55s, to attack the island of Gavutu, between Tulagi and Tanambogo. Paramarines and armored crewmen were issued the folding stock M55, and this version included a notable flaw: it's wire-frame stock was poorly designed, crude and flimsy, and had a tendency to fold while firing. Moreover, other serious shortcomings in both guns were becoming apparent. The reality was that the Reising was designed as a civilian police weapon and was not suited to the stresses of harsh battle conditions encountered in the Solomon Islands—namely, sand, saltwater and the difficulty in keeping the weapon clean enough to function properly. Tests at Aberdeen Proving Ground and Fort Benning Georgia had found difficulties in blindfold reassembly of the Reising, indicating the design was complicated and difficult to maintain. Many of the parts were hand fitted at the factory; this lack of parts interchangeability was not a problem for a civilian security or police firearm, but it was very problematic when Reisings were maintained in the field under combat conditions.