The installation of larger-bore cannons culminated in the fitting of the 40mm Bofors gun on the aft deck. Starting in mid-1943, the installation of this gun had an immediate positive effect on the firepower available from a PT boat. The Bofors cannon had a firing rate of 120 rounds/min (using 4-round clips) and had a range of . This gun was served by a crew of 4 men, and was used against aircraft targets, as well as shore bombardment or enemy surface craft.