The Caldwell machine gun is a

machine gun A machine gun is a fully automatic, rifled autoloading firearm designed for sustained direct fire with rifle cartridges. Other automatic firearms such as automatic shotguns and automatic rifles (including assault rifles and battle rifles) ar ...

of Australian origin developed by Thomas Frederick Caldwell in 1915.

History

The Caldwell machine gun was designed by Thomas F. Caldwell of

Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...

, who moved to the United Kingdom to bring his invention to the notice of

British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurk ...

authorities. The weapon was in appearance similar to the

Maxim gun The Maxim gun is a recoil-operated machine gun invented in 1884 by Hiram Stevens Maxim. It was the first fully automatic machine gun in the world. The Maxim gun has been called "the weapon most associated with imperial conquest" by historian ...

, but came with two barrels, capable of working in conjunction or separately with a discharge of 500

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

. It used pan magazines containing 104 rounds instead of the belt feed of the

, which was prone to jamming. As reported at the time: :"The Caldwell Machine Gun Company's invention of a quick-firing machine gun was recently sent to London in charge of Captain O. H. Moss and the inventor (Mr. T. F. Caldwell). The directors have now received information from their representatives and Messrs. Light and Fulton, solicitors to the company in London, that the gun has been sold, subject to certain conditions, for £5,000 in cash, £1 per gun royalty on all guns manufactured in Great Britain, and ten per cent of the consideration received from the sale of foreign rights or licenses The manufacturers are now completing a new gun under the supervision of Mr. Caldwell, whose services have been taken over at £1,000 per annum. The new gun will shortly be submitted to the Admiralty".

Overview

The weapon has two barrels and is chambered for the

.303 British The .303 British (designated as the 303 British by the C.I.P. and SAAMI) or 7.7×56mmR, is a calibre rimmed rifle cartridge. The .303 inch bore diameter is measured between rifling lands as is the common practice in Europe which follows th ...

round. The cooling jacket is similar to the Maxim gun but comes with a steam valve. The Caldwell is lighter and simpler than the Maxim and can be field-stripped in under one minute without the use of tools. The rate of fire of the Caldwell is variable as the gun is fired with a hand crank with the rate of fire dependent on the operator.

History

Overview

References

See also