The structural characteristics of American heavy machine guns M 19 19A6 in World War II.

M 19 19A6, like M 19 19A4, adopts the short recoil working principle of the barrel designed by Browning, locking the iron up and down. When shooting, as the warhead moves forward in the barrel, the barrel and bolt begin to recoil by 6 ~ 8 mm under the action of gunpowder gas pressure in the barrel, and at the same time, the barrel recoil spring and bolt recoil spring are compressed. When the warhead flies away from the muzzle, the locking iron leaves the locking bearing surface on the bolt, and the pin shafts at both sides of the locking iron are pressed down by the unlocking inclined surface on the shell, so that the locking iron descends away from the locking groove below the bolt, and the bolt is unlocked. The gun is designed with a cam "accelerator" mechanism, and the barrel sleeve in the recoil force hits the accelerator, making its upper end toggle the tail of the bolt to accelerate the recoil force of the bolt. In the recoil process of the bolt, the empty shell shell is pulled out by the shell extractor, and at the same time, the new shell is pulled out from the elastic belt by the shell extractor, and the new shell is guided by the arc groove above the shell cover to press the new shell toward the barrel axis. When the new shell is pressed, the empty shell is squeezed out and thrown out of the shell throwing window directly below the casing. At this time, because the lower end of the locking clip is blocked by the protrusion on the bottom surface of the housing, the cylindrical connecting sleeve cannot re-enter first. Only when the bolt is in place and the notch on it is aligned with the lock clip can the lock clip be lifted and loosened from the connecting sleeve. At the same time, the protrusion at the tail of the bolt hits the upper end of the accelerator to make it rotate forward, pushing the bolt and the barrel sleeve to re-enter the position together, and the locking clip is forcibly lifted under the action of the locking inclined plane of the bolt, so that the bolt is locked. At the same time, the plucking lever is clamped into the arc groove at the top of the bolt, so that the plucking plate can pull the next bullet to the bolt mouth, and the next bullet can be taken out, and at the same time, the new bullet aimed at the bolt chamber is pushed into the bolt chamber to enter the next firing cycle. The magazine entrance of M 19 19A6 is at the left front of the magazine, which can supply 250 metal magazines of M 19 19A4 machine gun and 250 canvas magazines of M 19 17 machine gun at the same time.

M 19 19A6 is lighter (including tripod) than M 19 19A4, which increases the maneuverability. Compared with M/KOOC-0/9/KOOC-0/9A6, M/KOOC-0/9/KOOC-0/9A4 mainly adds shoulder rest and flame suppression. The fishtail butt is added, and the upper end is almost horizontal and very long, which is the most important appearance feature for identifying guns. In the early M 19 19A6, like M 19 19A4, the muzzle only had a recoil device, and later it was changed to a horn-shaped flame arrester. The sight and ruler are located at both ends of the shell, the quasi-constellation can be folded, and the aiming baseline is short. The foldable handle is located at the joint of the barrel and the shell. There is a tripod in front of the radiator, but there is no tripod. But it still weighs 32.5 pounds. Actual combat has proved that it is too complicated to meet the ever-changing requirements of officers and soldiers on the battlefield. Even so, 43,487 guns were produced.

The M 19 19A6 machine gun quickly showed its unique advantages and outstanding performance in a series of subsequent mobile operations. M 19 19A6 can not only shoot in bipedal state, but also be used as a heavy machine gun by installing L-shaped connecting pin on the M2 tripod through the connecting hole under the gearbox like M 19 19A4 when necessary. The performance of M 19 19A6 machine gun is no less than that of its predecessor M 19 19A4, but the continuous firing time is slightly shorter, because in order to keep the mass of M 19 19A6 within a relatively reasonable range, a light barrel is adopted.

When M 19 19A6 repeatedly fires at the speed of 150 rounds per minute, the barrel starts to burn after 5 minutes. About half an hour, the average firing rate does not exceed 75 rounds per minute, and the barrel needs to be cooled. And it takes 3 minutes to change the barrel and 2 minutes to change the bolt, which is equally unpleasant. In contrast, the Maxim machine gun is much faster. It only takes 30 seconds to replace the barrel and 15 seconds to replace the bolt. On the battlefield, this time difference will bring life-threatening to soldiers. Therefore, in the Korean War, the machine gun shooter always prepared a full set of accessories for the barrel, barrel sleeve and bolt machine as much as possible, which could save 2 minutes.