BELL P-39 AIRACOBRA / P-63 KINGCOBRA 37mm AUTOMATIC CANNON SERVICING & ASSEMBLY FILM 17114

Want to support this channel and help us preserve old films? Visit This 1942 War Department training film (TF 1-311) gives viewers a look at how to strip and assemble the 37mm Automatic Gun M4. The film reviews the tools needed for the operations, then shows how to strip and assemble the tube (barrel), the breechblock and lock frame, the feed box, and the tube extension. It also instructs viewers on how to care for the weapon and remove and load the magazine. The film starts with a look at the M4. The film shows the tools needed to assemble the gun (01:01), which include a barrel bushing wrench, a strap pipe wrench, a piston rod nut wrench, a small screw driver, a crescent wrench, and pair of long-nosed pliers. The film first shows how to remove the tube (barrel); a man removes the lock frame on the gun. He uses a wrench to unscrew the locking nut on the tube (02:22). Then the man applies the strap pipe wrench and disconnects the tube bushing. He uses a screwdriver to remove the two halves. The film then shows how to replace the tube (03:40), screwing the tube into the gun by hand and then tightening with the barrel bushing wrench. Next, viewers see how to remove the breechblock (04:55). The man removes the cover and rotates a spring lever under the gun to move it out of the way. He removes the back plate and takes the lock frame out of body of the gun (06:02). The film shows the lock frame (06:44), and the man inserts a screwdriver to release the head and follower of the operating lever spring. He continues by removing the operating lever pin and sets aside the operating lever. Viewers see how the hammer pin is removed (09:03), as well as the guide and spring of the lock frame. The man continues to disassemble the hammer. The film then shows how to reassemble the lock frame, working in reverse. The man tests the assembled lock frame (13:20). He pushes the breechblock up into position on the gun case and inserts the lock frame, releasing the carrier catch first. Once in, the back plate is replaced. The film goes over how to remove and disassemble the feed box next (14:52). The man removes the feed lever pin and feed lever. He removes the feed slide lever and feed side bridge. He uses a screw driver to remove the carrier pin by loosening the screw (16:24). He removes the plunger and spring from the feed box. The film then shows how to reassemble the feed box components (17:45). He tests the reassembled feed box. Next, the film covers the removal of the tube extension. The man removes the driving springs as the first step to remove the tube extension (20:10). He compresses the breechblock and then uses a wrench to remove a nut for the tube extension, which is then removed through the rear of the gun. A close-up shot shows the trigger pin being removed (21:50), as well as the trigger lever plunger and spring. Then the film shows the reassembly of the tube extension. The film briefly shows how to care for the M4, as the man cleans the barrel and oils the weapon. He uses a brush to apply oil lubricant to the various pieces of the gun (24:12). Next, he removes the filing plug from the recuperator cylinder and adds oil to the cylinder (25:05). He taps the cylinder with his hand to remove any air bubbles. Lastly, the film shows how to remove and load the magazine. The man removes the belt of the magazine first (26:22), removing a pin with pliers and lifting off the cover. He slowly removes the belt from the magazine. He removes the cotter pins and bolts from the top of the magazine (27:35), then he removes them from the magazine pin. He removes the right half of the magazine, and the film shows the gun with just the left half mounted. The film then shows the magazine mounted on the gun, and the man removes the lower right-side plate to load thirty rounds (29:12). He replaces the plate and pulls the lock frame to the rear to prepare the gun for firing. The film then concludes with a shot of what appears to be a Bell P-63 Kingcobra flying in the sky. The 37 mm Automatic Gun, M4, known as the T9 during development, was a 37 mm ( in) recoil-operated autocannon designed by Browning Arms Company. The weapon, which was built by Colt, entered service in 1942. It was used in the Bell P-39 Airacobra and P-63 Kingcobra. We encourage viewers to add comments and, especially, to provide additional information about our videos by adding a comment! See something interesting? Tell people what it is and what they can see by writing something for example: “01:00:12:00 -- President Roosevelt is seen meeting with Winston Churchill at the Quebec Conference.“ This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit