The development of the US military M7 grenade launcher background
When the front line of World War II was getting bigger and bigger, the United States participated in World War II at the end of 1941. At that time, American soldiers mostly chose to use soldiers to throw Mk 2 fragmented grenades by hand. In order to make soldiers throw farther, the Mk 2 fragmented grenade equipped at that time did not charge much, so its lethality was very limited. In addition, the range of soldiers throwing bare hands was only about 30 meters, so it could not pose a threat to the armored vehicles at that time. Under this background, the US military began to develop a launcher that can be used to launch a more charge and a longer range. This launcher is the M7 grenade launcher that Lao Bai will analyze with you in this issue.
Unique air-conducting design
M7 grenade launcher developed in World War II. In fact, the United States had a grenade launcher as early as World War I, and at that time it used the V-B grenade launcher from France.
However, this launcher has many problems and has poor adaptation with the 7.62mm rifle shell used by the US military. Therefore, it is easy to directly detonate the grenade when used, so it was quickly eliminated. Then, based on this as a model, the US military began to develop a new M series grenade launcher on its own. The M7 grenade launcher in this issue is more widely used.
M7 grenade launcher started mass production and put into service in 1943. The overall external design is very simple and can be divided into two parts. One part is the connecting bracket used to connect the rifle muzzle, and the other part is the tubular grenade retainer. The overall length of
is 190.5 mm. The connector is an L-shaped structural design. When used, the connector is installed on the muzzle and is fixed to the barrel through a movable mechanism at the rear.
also has a rifle air closure device on the connector. When installed, this protrusion will be installed in the rifle's air crocodile, so that the air hole can be closed when the grenade is fired. The advantage of this design is that it can reduce the loss of pressure in the barrel during firing, increase the utilization rate of gunpowder gas and slow down the resitting speed of the bolt. From this we can see that if it is a semi-automatic rifle, after installing the M7 grenade launcher, the launching medicine gas will no longer be used to complete the movement of the bolt. Therefore, after the firing is completed, the shell and loading need to be manually extracted. Another part of the
M7 grenade launcher is a tubular structure. The surface of this structure is designed with grooves. The function of these grooves is not to dissipate heat, but to adjust the launch distance when installing grenades.
will be designed with digital markings on each groove. Each scale represents a different launch distance. When installing a supporting grenade, installing it in different positions will cause different internal spaces. Similar to the principle of the Japanese Type 89 grenade introduced in the previous issue, the initial speed of the launch can be adjusted, thereby adjusting the launch distance. During installation, the required scale position of the grenade is fixed through a clip. After the installation of
, the selected grenade was installed on the M7 grenade launcher and then it could be fired. At that time, the US military was mainly equipped with M9 anti-tank grenades.
This grenade consists of a grenade adapter at the lower part and a warhead at the upper part. The adapter is mainly used for connection with the grenade launcher. The upper warhead and the lower part are not connected. It is connected to the M7 grenade launcher through the lower part for firing. When using the
M7 grenade launcher, the ammunition needs to be launched using a special large-capacity launcher with empty packs of medicine. The principle is similar to the Japanese 100-type grenade, which uses high-pressure gunpowder gas generated by firing ammunition to push the grenade launch.The difference between
is that the Hundred-type grenade can be fired using normal ammunition, while the M7 grenade launcher cannot use normal ammunition because the bullet will cause damage to the barrel or cause the grenade to explode. Therefore, when the M7 grenade launcher was in use, he chose an empty bullet with a warhead as wood. After firing, the wooden bullet and high-pressure gas hit the bottom of the grenade together to fire it.
M7 rifle grenade launcher can also fire M19 with white phosphorus smoke/combustion warhead and M17 rifle grenade with fragmented warhead.
At that time, the M7 gun grenade launcher was mainly used with the M1 Garland rifle. When firing, the butt stock needs to be placed on the ground, and the rifle is used at an angle of 45° with the ground. However, there are also cases where the butt stock is pressed against the shoulder to shoot.
M7 grenade launcher with M9 series anti-tank grenade can achieve a maximum range of 228.6 meters, which is greatly increased than the range of more than 30 meters with hand throws.
Later, in order to increase the range, a set of auxiliary range-extended fuel was added to the bottom of the grenade. Before installing the grenade, it can be placed in the muzzle of the grenade launcher facing the ammunition chamber. When it is fired, it will be ignited and increased the chamber pressure, which will increase the initial speed of the grenade by about 50%. This range-extended design can increase the range by 10 meters.
Although the M7 grenade launcher is not very recoiled when it is launched, there will be a situation where the recoil will cause wear and jam of the launcher and barrel structure. Therefore, the designer installed a set of grenade retaining springs on the front end of the tubular mechanism to solve this problem. After the
M7 grenade launcher was put into service, it has undergone many improvements and upgrades. There are three versions of M7A1, M7A2 and M7A3, which are used in World War II, Korean War and Vietnam War.
In the Vietnam War, because the efficiency of this grenade launcher was relatively low, the US military began to develop more efficient anti-tank weapon M72 type 66mm bazooka . So soon after, it was replaced by the more efficient M72 type 66mm bazooka, ending its service career.
