Ordnance QF 25-pounder

The Ordnance QF 25-pounder, or more simply, 25-pounder or 25-pdr, was introduced into service just before World War II, during which it served as the major British field gun/howitzer. Combining high rates of fire with a reasonably lethal shell in a highly mobile piece, it was the British Army's primary artillery field piece well into the 1960s, with smaller numbers serving in training units until the 1980s. Many Commonwealth of Nations countries used theirs in active or reserve service until about the 1970s and ammunition for the weapon is currently being produced by Pakistan Ordnance Factories.

Design
The design was the result of extended studies looking to replace the 18-pounder (3.3 in bore) field gun and the 4.5-inch howitzer (114.3 mm bore), which had been the main field artillery equipments during the First World War. The basic idea was to build one weapon with the direct-fire capability of the 18 pounder and the high-angle fire of the howitzer, firing a shell about half way between the two in size, around 3.5 - 4.0 in of about 30 lb.

Development during the inter-war period was severely hampered by a lack of money and it was eventually decided to build a "new" design from existing 18 pounders by converting barrels but designing a new barrel and carriage for production when funds were available. The result was a 3.45 in weapon firing a shell weighing 25 lb. It was mounted on late model 18 pounder carriages. One of these used a circular firing platform and this was adopted for the new guns. The firing platform was lowered and the gun pulled onto it, providing a flat smooth surface for the road wheels that allowed the gunners to quickly traverse the weapon in any direction.



Unlike the 18-pounder, the 25-pounder used howitzer-type variable-charge ammunition. For the Mk 1 Ordnance on 18-pounder carriage there were three "charges", Charge 1, 2 and 3 in a single cartridge. The 'proper' 25-pdr, Mk 2 Ordnance on Mk 1 Carriage, also had charge Super in a separate cartridge. An increment for charge Super was introduced in 1943 to provide higher velocity for anti-tank shot. Subsequently another type of increment was introduced to be added to charges 1 and 2 to provide three additional charge combinations for use with upper register (high angle) fire. The introduction of the increment to charge Super was only possible following the addition of the muzzle-brake in the previous year.The 25-pounder was separate-loading, the shell was loaded and rammed then the cartridge in its brass case was loaded and the breech closed. In British terminology the 25-pounder was called "Quick Firing" (QF) because the cartridge case provided obturation (it provided the gas seal in the breech) and was automatically released when the breech was opened.

In common with all British guns of the period the indirect fire sight was "calibrating". This meant that the range, not elevation angle was set on the sight. The sight compensated for the difference in the gun's muzzle velocities from standard. The gun was also fitted with a direct-fire telescope for use with armour-piercing shot. It also used "one-man laying" in accordance with normal British practice.

An important part of the gun was the ammunition limber ("Trailer, Artillery, No 27"). The gun was hitched to it and the trailer hitched to the tractor when on tow. The gun did not need a limber and could be hooked directly to a tractor. The trailer provided the brakes as only a hand-brake was fitted to the gun carriage The trailer carried ammunition; thirty-two rounds in trays (two rounds per tray) in the trailer protected by two doors. Ammunition was also carried in the gun tractor with the detachment and various gun stores. Some stores, such as sights, were carried cased on the gun. Each section (two guns) had a third tractor that carried ammunition and towed two ammunition trailers.

The gun detachment comprised the following: No 1 - detachment commander (a sergeant), No 2 - operated the breech and rammed the shell, No 3 - layer, No 4 - loader, No 5 - ammunition, No 6 - ammunition, normally the 'coverer' - second in command and responsible for ammunition preparation and operating the fuze indicator.

The official 'reduced detachment' was four men.

Many different Companies manufactured the guns and component parts in the UK. Vickers Armstrong in Scotswood, Baker Perkins in Peterborough and Weirs in Glasgow were some of the most significant. The various Royal Ordnance factories produced most of the ordnance components. In Canada Sorel Industries built complete guns and provided the ordnance for fitting to the Sexton. Australia also built complete guns, choosing to weld the carriages rather than rivet, as was the practice in the UK and Canada. In all, over 13,000 were made world wide.

Ammunition


The 25-pounder fired "separate"or two-part ammunition—the projectile and the propelling charge in its (usually brass) cartridge case with its integral primer were loaded separately. Typically for a quick-firing gun, the cartridge case provided obturation.

There were two types of cartridge. The "Normal" cartridge contained three cloth charge bags (coloured red, white and blue). White and/or blue bags would be removed from the cartridge to give "Charge 1" or "Charge 2", leaving all three bags in the cartridge case gave "Charge 3". The cartridge case was closed at the top with a leatherboard cup. The second type of cartridge was "Super", which provided one charge only. The cup could not be removed from the cartridge case. In 1943, an Incremental Charge of 5.5 oz of cordite ("Super-plus") was introduced to raise the muzzle velocity when firing AP shot with charge Super; this required a muzzlebrake to be fitted. Adoption of "upper-register" (high-angle) fire needed more charges to improve the range overlap. This led to the development of the "Intermediate Increment" of 4oz cordite, which was introduced in 1944. The bags were striped red and white to indicate that they should only be used with Charges 1 and 2. When one bag was used with Charge 1 it provided Charge 1 1/2. When one was added to Charge 2 it provided Charge 2 1/3, and two bags, Charge 2 2/3. This allowed a maximum of seven charges instead of four.

There were many marks of cartridge, mostly differentiated by propellant type. Double-base propellant (nitrocellulose/nitroglycerine) was the UK standard but one mark used US single-base (nitrocellulose only). However, triple-base nitrocellulose/nitroglycerine/picrite was used throughout the war and eventually replaced all others.



The 25-pounder's main ammunition was the high-explosive (HE) streamlined shell with a 5/10 CRH ogive and boat tail. It was also provided with base ejection smoke (white and coloured), star shells, and chemical shells. Incendiary and coloured flare shells were developed but not introduced into service, and smoke shells were sometimes reloaded with propaganda leaflets or metal foil "window". The UK did not develop a WP smoke shell for the 25-pounder.

For anti-tank use, the 25-pounder was also supplied with a limited amount of 20 lb solid armour-piercing (AP) shot, later replaced with a more potent version with a ballistic cap (APBC). The AP shot was fired with maximum charge, Charge No. 3, Super, or Super with Super Increment depending on the ordnance mark, as muzzle velocity was critical in direct fire for penetration and a flat trajectory.

A shaped charge anti-tank shell was under development in Canada, but the introduction of the QF 17 Pounder, an anti-tank gun, in 1944 ended its development. After the Second World War, the UK replaced AP shot with a HESH shell. Coloured marked shells (dye and PETN) were also developed but not introduced.

The standard fuze is No 117 Direct Action (DA). No 119 (DA and graze) was also used. Combustion or mechanical time fuzes were used with base ejection shells and mechanical time with graze were used with HE. VT fuzes were used from the end of 1944 and subsequently replaced by CVT fuzes.

British service


The 25-pounder was the main field artillery weapon used by British Commonwealth and colonial infantry and armoured divisions of all types during the Second World War. Throughout the war each British-pattern infantry division was established with 72 25-pounders, in three field artillery regiments. Armoured divisions eventually were standardised with two field artillery regiments, one of which was self-propelled (see below). Before mid-1940 each regiment had two batteries of twelve guns; after that date regiments changed to batteries of eight guns and added a third battery, a process that was not completed until early 1943. In the late 1950s, the British Army reverted to batteries of six guns. Field artillery regiments had two batteries of 25-pounders and one of 5.5 inch guns.

The early 18- and 25-pounders had been towed in the field by the Light Dragon, a tracked vehicle derived from a light tank, and the Morris CDSW. Throughout most of the Second World War the 25-pounder was normally towed, with its limber, behind a 4x4 Field Artillery Tractor called a "Quad". These were manufactured by Morris, Guy and Karrier in England, and, in greater numbers, by Ford and Chevrolet in Canada. In the 1950s, the British Army replaced the various "Quads" with a new Bedford 3-ton gun tower fitted with a specialist body.



In 1941, the British Army improvised a self-propelled 25-pounder named the Bishop, on the chassis of the Valentine tank. This mount was unsatisfactory and was replaced in 1942 by the American M7 Priest. However, this complicated the supply of ammunition in the field, and was replaced in 1944 by the Sexton, which was designed and mostly manufactured in Canada (some 2/3 of ordnances and mountings were imported from the UK due to limited Canadian production capacity) and mounted the 25-pounder on a Ram or Grizzly tank chassis.

By World War II standards, the 25-pounder had a smaller calibre and lower shell-weight than many other field-artillery weapons, although it had longer range than most. (Most forces had entered the war with even smaller 75 mm designs but had quickly moved to 105 mm and larger weapons.) It was designed for the British practice of suppressive (neutralising) fire, not destructive fire that had proved illusory in the early years of World War I. Nevertheless the 25-pounder was considered by all to be one of the best artillery pieces in use. The effects caused by the gun (and the speed at which the British artillery control system could respond) in the North-West Europe Campaign of 1944–1945 made many German soldiers believe that the British had secretly deployed an automatic 25-pounder.

In UK service most guns were replaced by the 105mm Abbot and some by the Oto Melara 105mm Pack Howitzer and the remainder by the 105mm L118 Light Gun. The last British military unit to fire the 25-pounder in its field role (as opposed to ceremonial use) was the Gun Troop of the Honourable Artillery Company on Salisbury Plain in 1992.

Service with other nations
In addition to Commonwealth and colonial forces other Second World War users included the free forces of France, Greece, Poland, Czechoslovakia, Netherlands, Belgium and Luxembourg. The first shot fired by US artillery against the German army in World War II was from a 25-pounder of the 34th Infantry division.

After the Second World War 25-pounders remained in service with many Commonwealth armies into the 1960s. They were used in Korea by British, Canadian and New Zealand regiments and in Malaya by British and Australian batteries. They also featured in wars on the Indian sub-continent and in the service of Israeli and other Middle Eastern armies.

Since leaving UK service, the last users of the 25-pounder in combat have been the Special Air Service advisors to the Omani Army during the 1972 Battle of Mirbat in Oman, the Cypriot National Guard during the 1974 Turkish invasion of Cyprus and by Kurdish militias in northern Iraq in 2003.

South Africa
The gun was called G1 by the South African Defence Force. It was extensively used in the early stages of the South African Border War, including Operation Savannah. The G1 is still used in the ceremonial role.

Rhodesia
The Rhodesian Army used the weapon during the Bush War but by this stage the round could not penetrate enemy bunkers.

Sri Lanka
The 25-pounder was extensively used by the Sri Lankan Army during the early years of the Sri Lankan civil war. It still remains in service, although only in a ceremonial role.

Ireland
In 1949, 48 ex-British-Army Mark III 25-pounders were acquired by the Irish Defence Forces and were in service with the Reserves until 2009, having been replaced in the Army by the 105 mm Light Gun in 1981. The Irish Army maintains a 6-gun ceremonial 25-pounder battery for use on state occasions.

India
The Indian Army employed the 25-pounder into the 1980s. They were last used in combat during the assault on the Sikh Golden Temple in 1984.

Luxembourg
The Luxembourg Army maintains a number of 25-pounder guns rebarrelled to 105 mm and fitted with new sights for gun salutes.

Greece
The 25-pounder first entered service with Greek forces in North Africa during WWII. Three (I,II & III) field artillery regiments of 24 tubes were created in total as part of the Greek infantry brigades created. They saw significant action at El Alamein and Rimini. After the war the 25-pounder served as part of the Greek Army during the Greek Civil War. A total of 125 25-pounder guns were used by the Greek artillery during the Civil War of 1946-1949, in various organizational schemes. After the Civil War they were organized into seven independent regiments of 18 guns. Following Greece's entry into NATO in 1952 and the standardization on American calibres in 1953, the 25-pounders were not retired (unlike other models), but were reorganised as 13 battalions of eight guns in divisional artilleries. In 1957 the influx of American artillery pieces permitted an increase from 8 to 12 guns per battalion. In 1964 a total of 54 25-pdr guns were delivered from Greece to Cyprus, where they entered service with the Cyprus National Guard organized into 4 battalions of 12 guns (181, 182, 183 and 185) and one independent battery of six guns (184). They saw action during the Turkish invasion of the island in 1974. The 25-pounder remained in Greek Army service until 1992, when it were retired as part of the CFE agreement. The guns of the Cyprus National Guard remain in storage.

Mark I


Known officially as the "Ordnance, Quick Firing 25-pounder Mark I on Carriage 18-pr Mark IV", or "Ordnance, Quick Firing 25-pounder Mark I on Carriage 18-pr Mark V" and commonly called the "18/25-pounder". The Mark I was a 25-pounder barrel and breech in the modified jacket of an 18 pounder gun, as a 'loose liner'. The jacket provided the interface to the 18 pounder carriage. The earliest versions retained 18-pounder type elevation sights but later ones had Probert pattern calibrating sights on the right side of the saddle. The Mark IV P, carriage was a box trail, Mark V P, was a split trail. These conversions of the 18-pounder first entered British service in 1937. A few were lost in the Norwegian campaign and 704 in France, leaving about the same number in UK's global stocks. They served in North Africa (until about late 1941) and India. This mark of 25-pounder was limited to charge 3 due to its 18-pounder carriage.

Mark II


The Mark II, fitted to the Mark I carriage was the standard gun during World War II. They were built in Australia and Canada but mostly in UK. Deliveries (from UK production) started at the beginning of 1940 and first entered service with a Canadian regiment stationed in UK during May 1940. No Ordnance 25-pr Mk 2 on Carriage 25-pr Mark 1 were lost in France. This gun fired all charges, 1 - 3 and Super. In 1942 it was decided to fit a muzzle brake to the gun. This was to eliminate the instability caused when firing the 20 lb AP shell with Charge Super at direct fire low elevation angles. To preserve the gun's balance on the trunnions a counterbalance weight was also fitted, just in front of the breech ring. These modifications did not lead to a change in the gun's nomenclature. Eventually all guns serving in Europe were so converted.

Mark II/I
In 1946 a programme was introduced to modify the gun's breech ring by morticing the rear corners. A corresponding modification was made to the rear corners of the breech block. This was to reduce the instances of cracking the ring.

Mark III
The Mark III ordnance was a Mark II with a modified receiver to prevent the rounds from slipping back out when loading at high angles. It was introduced in January 1944.

Mark III/I
This was a Mk III gun with the same modification to the ring and block as for the Mk II/I above'.

Mark IV
The Mark IV was identical to the Mark III/I, and featured the modified ring and a paired block from new.

Short, Mark I


The 25-pounder Short Mark I, or Baby 25-pr, was an Australian pack gun version of the 25-pounder, first produced in 1943. This was a shortened version of the standard 25-pounder, mounted on the Carriage 25-pr Light, Mark 1. The Baby was intended for jungle warfare and was only used by Australian units in the South West Pacific theatre of World War II. The gun could be towed by a jeep or broken down into 13 sections and transported by air. During the New Guinea campaign the gun was manhandled up steep jungle tracks where trucks could not operate.

Mark I
The Mark I carriage was the first real 25-pounder carriage. Later in World War II some guns had a double shield, two shields separated by spacers, to improve protection. It had Probert-pattern calibrating sights, but with the range indicator wrapped into the distinctive cone that rotated against a fixed reader arm.

Jury axle
In Burma artificers of 129 Jungle Field Regiment developed a local modification to use a Jeep axle and wheels to produce a narrower wheelbase (by about 20-inches) and some minor modifications to the trail, it was called the Jury Axle. Tests in action showed the gun was stable, it was first reported to GHQ India in October 1943. It appears that it was also used without its shield, and the gun could be disassembled for transport in pieces by Jeep.

Mark II
The Mark II carriage was basically the War Office approved formalisation of the Jury Axle version of the Jury Axle 25-pounder. Changes from the original included a narrower shield, a new narrower track platform (No 22) and modified Jeep wheels.

Mark III
The Mark III carriage, also narrow, was a further development of the Mark II carriage to provide joints that enabled the trail to be cranked for "upper register" (high-angle) fire and used with the cranked "dial sight adaptor" previously adopted for high-angle fire. The cranked trail meant that a trail pit did not have to be dug. It entered service soon after World War II. High-angle fire had been introduced in Italy and used increments to charges 2 and 3 to give the 25-pounder seven charges.

Mark IV
The British did further work on the Australian designed short 25-pounder, enabling it to fire charge Super. One or 2 prototypes were produced and the carriage was officially designated the Mark IV, but never went into production.

Bishop
The Bishop was a British self-propelled 25-pounder using the Valentine tank chassis.

Sexton
The Sexton was a Canadian self-propelled 25-pounder using the Ram or Grizzly tank chassis.

Yeramba
The Yeramba was an Australian self-propelled 25-pounder using the M3 Lee tank chassis.

Users

 * 🇦🇺 Australia
 * 🇧🇪 Belgium (Used by Belgian Field Battery during Second World War)
 * 🇧🇷 Brazil
 * 🇨🇦 Canada
 * 🇨🇾 Cyprus
 * 🇫🇯 Fiji (relegated to ceremonial role)
 * 🇬🇷 Greece
 * 🇮🇪 Ireland (relegated to ceremonial role)
 * Kingdom of Italy (Captured examples and 1943-45 co-belligerent forces)
 * 🇱🇧 Lebanon
 * 🇱🇺 Luxembourg (relegated to ceremonial role)
 * 🇲🇹 Malta (relegated to ceremonial role)
 * Nazi Germany (Captured examples)
 * 🇳🇿 New Zealand
 * 🇴🇲 Oman
 * 🇵🇾 Paraguay 12 Army (from South Africa)
 * 🇵🇱 Poland
 * 🇵🇰 Pakistan: 1000 in service with the Pakistan Army.
 * 🇵🇹 Portugal
 * Rhodesia
 * 🇸🇬 Singapore (relegated to ceremonial role)
 * 🇿🇦 South Africa (relegated to ceremonial role)
 * 🇱🇰 Sri Lanka (relegated to ceremonial role)
 * 🇬🇧 United Kingdom