A US Army Mark 31 Quadruple. 50cal mount

[Subdeacon Joe]

An unusual sight on a US Navy warship. A US Army Mark 31 Quadruple. 50cal mount alongside a twin 20mm Oerlikon mount. The weapons were mounted on the Essex class aircraft carrier USS Lexington (CV-16).

 

Continuing on with belt-fed ammunition, let's talk about an experiment that tested the quad .50 aboard warships. 

 

The test was to determine the effectiveness of the .50 cal mount at sea and test it's use as an anti-kamikaze weapon. 

 

Six mounts were installed on Lexington in May of 1945 and operated alongside the other anti-aircraft weapons. The mount was the standard Army model, featuring its own self contained power system, and was not significantly modified for use on a Navy ship. 

 

After a few months of operation, the US Navy found that the weapon had several advantages. 

 

- Utilizing a powered mount, the quad .50 was found to be more accurate as the operation was smoother when tracking targets compared to the hand-directed 20mm Oerlikon. 

 

- The use of belt-fed ammunition allowed the quad .50 to typically fire for the entire duration of a typical air attack before needing to reload. This was seen as a major advantage over the 20mm which had to pause between bursts to reload its drum magazine. 

 

- The self contained power system was seen as particularly advantageous. While the 20mm was a manually-directed weapon, the sighting system required an external powersource which was supplied by the ship. In the event of a ship losing power, the 20mm mounts lost their sighting system. The quad .50 used its own generator and battery pack to produce power. This allowed the mount to remain in action even if the ship lost power. 

 

Of course there were disadvantages as well. 

 

- The .50 cal machine gun round lacked the necessary stopping power needed to intercept aircraft, requiring more hits. 

 

- The reload time was about 2x to 3x greater than the 20mm Oerlikon. During a major sustained air attack, the .50 would have larger pauses between firing to reload.

 

- The barrels on the .50 cal mounts were designed for Army use. They had significantly less barrel life compared to the 20mm weapons. 

 

- The mounts were temperamental at first and required greater maintenance. However, this may have been due to unfamiliarity with such systems. Later reports state the weapons became highly reliable as the crew learned how to maintain them. 

 

Overall, the Navy judged a single quad .50 mount to be roughly equivalent to a twin 20mm mount. However, they would not pursue the installation of the quad .50 on warships. 

 

Instead, they called for the development of a quad 20mm mount featuring belt-fed ammunition. Such a weapon system was seen as the best way of combining the various advantages of both systems into one platform.

 

We will take a look at the 20mm quad mount projects in future posts. 

 

Photo from Navsource

 

7

[Chickasaw Bill SASS #70001]

I want one to mount on the 5 ton 

 

  can ya say  GUN TRUCK 

 

  I knew ya could 

[Forty Rod SASS 3935]

2 hours ago, Chickasaw Bill SASS #70001 said:

I want one to mount on the 5 ton 

 

  can ya say  GUN TRUCK 

 

  I knew ya could 

Saw a bunch of those in 'Nam.  Jerry rigged and no two were alike.

[Sedalia Dave]

5 hours ago, Chickasaw Bill SASS #70001 said:

I want one to mount on the 5 ton 

 

  can ya say  GUN TRUCK 

 

  I knew ya could 

 

 

[Rip Snorter]

Had a history teacher in HS, a vet who had lost part of an arm in Korea.  He talked about the quad 50 obliterating a human wave charge. if I recall all these decades later, in the retreat from Frozen Chosin.  https://www.koreanwaronline.com/arms/50quad.htm

[Chantry]

In addition to the Quad .50's being used in the anti-aircraft role, it was also used to suppress snipers, mainly by shooting down the tree the sniper was in.   As mentioned it was also used in countering mass attacks or ambushes, with devastating results.

 

https://en.wikipedia.org/wiki/M45_Quadmount

 

http://www.robertsarmory.com/quad.htm

 

 

 

[DeaconKC]

I always wondered why they never built a .50 caliber "Minigun". On a Bradley or Humvee, it would be a great urban weapon.

[largo casey #19191]

They  h ad the VULCAN 20mm  Deacon

                                                             Largo

[Chantry]

14 minutes ago, DeaconKC said:

I always wondered why they never built a .50 caliber "Minigun". On a Bradley or Humvee, it would be a great urban weapon.

 

Made as a 3 barreled "minigun"  https://en.wikipedia.org/wiki/GAU-19

 

I suspect weight of the gun plus a useful amount of ammo was too much for the HUMVEE and over penetration in urban environment might be a concern as well.

 

[DeaconKC]

3 hours ago, Chantry said:

 

Made as a 3 barreled "minigun"  https://en.wikipedia.org/wiki/GAU-19

 

I suspect weight of the gun plus a useful amount of ammo was too much for the HUMVEE and over penetration in urban environment might be a concern as well.

 

Thanks!

[watab kid]

would be fun to get a go at that , 

[Sedalia Dave]

When it comes to the Bradley, the 25mm Bushmaster beats the 50 Cal hands down.

 

 

[Chickasaw Bill SASS #70001]

where ya gonna find dies for it ? 

[Subdeacon Joe]

2 hours ago, Chickasaw Bill SASS #70001 said:

where ya gonna find dies for it ? 

 

 

Meet with the Ordnance Sergeant,  bring whiskey.