BRITISH ARTILLERY IN WORLD WAR 2

 25-PDR

Updated  14 June 2014

Conversion factors to metric measurement

 Ordnance Q.F. 25-pr Mk 2 on Carriage 25-pr Mk 1

 Picture List

The 25-pr Gun Mk 2 on Carriage 25-pr Mark 1 was the standard British field gun of World War 2, consequently it was widely used, in addition to Commonwealth artilleries it was used by the Free Forces of Poland, France, Netherlands, Belgian and Greece.  It was manufactured in UK, Canada and Australia (1315 guns). Deliveries started at the beginning of 1940 and the first entered service in April and completed field service in the British Army in 1967, although it was retained in some training units until the early 1980's.  UK and Australia last used them operationally in Malaya in the 1950's.  It was last seen in action in April 2003 with Kurdish forces in N Iraq.  During WW2 ammunition was produced in Australia, Canada, India, South Africa and UK.

Calibre

 3.45 inches

Ordnance length
Bore length

 97.45 inches
 26.7 calibres

Rifling

 26 grooves, 1 in  20 uniform twist

Chamber capacity

 151 cubic inches

Barrel

Autofrettaged loose liner

Breech

Vertical sliding block

Recuperator

Hydro-pneumatic

 Sights

 Calibrating &  reciprocating

Carriage configuration

 Box trail &  platform

Elevation

  - 5° to 45° & 70°
 Note 2

Top traverse
Platform

 4° Left & Right
360° 

Loading Angle

 Any

Basic Weight

 1.8 tons

Length (muzzle to towing eye)

 15.1 feet

Trunnion height

 3.8 feet

Width at wheel hubs

 7 feet

Standard HE Shell Mk 1D

Length (less fuze)

 13.84 inches

Calibre radius head

 5/10

Body Diameter

 3.44  inches

Driving Band Diameter

 3.56  inches

Weight (incl fuze)

 25 lbs

Explosive Weight

 1.8 lbs

Charge

New Gun MV

RT MV

RT Max Range

Time of Flight @ Max Range

Probable Error @ Max Range

Approx  Propellant Weight

 Remarks

 1

 650 f/s

650 f/s

3,900 yds

25 secs

 45 yds

0.4 lbs

 Red bag

 2

 1000 f/s

975 f/s

7,800 yds

38 secs

 35 yds

0.5 lbs

 Red & White bags

 3

 1486 f/s

1450 f/s

11,825 yds

51 secs

 35 yds

0.8 lbs

 Red, White & Blue bags

 Super

 1747 f/s

1700 f/s

13,400 yds

53 secs

 40 yds

 2.7 lbs

 Separate cartridge

Supplementary intermediate charge increments ( 4 oz) for upper register fire Note 3

1 + 1 inc

877 f/s

825 f/s

5,900 yds

33 secs

50 yds

0.7 lbs

2 + 1 inc

1169 f/s

1150 f/s

9,700 yds

43 secs

50 yds

0.8 lbs

2 + 2 incs

1328 f/s

1300 f/s

10,700 yds

43 secs

45 yds

1.0 lbs

Anti- tank shot (20 lbs)

3

1550 f/s

2,000 yds

5 secs

 All Mks of guns

Super

1880 f/s

1850 f/s

3,000 yds

7.2 secs

 Mk 2 and later guns

Super + super inc

2000 f/s

3,000 yds

6.9 secs

 Mk 2 and later guns with muzzle brake

Rates of fire

Gunfire

Intense

Rapid

Normal

Slow

Very slow

Rounds/Minute

 6 to 8

 5

4

3

2

1

Normal Detachment

 6 men
(reduced - 4)

Gun Tractor

 Field Artillery Tractor  4 × 4

Artillery Trailer

 No 27

1st Line Ammo (per gun)

 114 HE
 16 Smoke
 12 AP

TOWED VARIANTS

Gun Mk 1: invariably called the '18/25-pr', this was a 25-pr barrel and breach in the modified jacket of an 18-pr as a 'loose liner'.  The jacket provided the interface to the 18-pr carriage.  The earliest versions retained 18-pr type elevation sights but later ones had Probert pattern calibrating sights but on the right side of the saddle.

Carriage 18-pr: only used with Mk 1 Gun.  It was either the 18-pr Mk 4P (box trail) or Mk 5P (split trail) carriage. These guns equipped the BEF in 1939-40 and some units in the Middle East and India.  They used 18-pr type sighting arrangements.

Guns Mk 2 to 4: designed as a loose liner to fit the short jacket of a 25-pr.  Mks 3 and 4 varied slightly in internal shape of their chambers and breech. In 1943 guns in the Western theatres were fitted with muzzle brakes so that they could fire AP shot with Charge Super + super increment.  This meant modifying the barrel and these were designated Mk 2/1 and 3/1.  Mk 4 was designed to take the muzzle brake.

Carriage Mk 1: the first 'real' 25-pdr carriage, its box trail and platform were from a Vickers design for a 105-mm howitzer developed in 1930.  Later in the war some guns had a double shield, two shields separated by spacers, to improve protection.  It had a Probert pattern calibrating sights, but with the range indicator wrapped into the distinctive cone that rotated against a fixed reader arm.

Jury Axle: a local modification developed in Burma by 2 NCOs of 129 Jungle Field Regt in 1943.  It reduced the gun width to that of a Jeep and was narrow enough to be loaded into a Dakota aircraft without disassembly.  It could also be broken down into jeep loads.

Carriage Mk 2: basically formalisation of the Jury Axle and shield with additional modifications and new narrower track No 22 platform.  It was about 20 inches narrower than the standard Mk 1 carriage.

Carriage Mk 3:  Mk 2 Carriage further developed to provide joints that enabled the trail to be cranked for upper register fire.  It entered service at the end of the war.

25-pr Short Mark 1 (Australian).  This had a reduced length barrel and was designed to be split into pack loads.  It was only produced and used by Australia (212 guns), and went out of service at the end of the war.  More details below.

UK did further work on the 'Short', enabling it to fire charge super.  One or 2 prototypes were produced and the carriage was officially designated Mk 4, but never went into production.

In the early 1950's prototypes of a new 88-mm long barrelled gun firing 25-pr ammunition were developed, it was planned to develop a new 22 lb high lethality shell to give 17000 yards range.  Often called the Garrington gun, it had a novel carriage design, a platform, overhead protection and was about 1 ton heavier than 25-pr.  It did not enter service.

SELF PROPELLED VARIANTS

The first self propelled variant was mounted on a Valentine tank, 'Carrier, Valentine, 25-pr, Gun, Mk 1' and commonly named 'Bishop'.  Only 150 were produced and issued during May - Oct 1942. It was not a successful design.  

The US production of 105-mm M7 SP led to a 25-pr version, designated 25-pr T32 and subsequently T51.  A prototype seems to have been produced. The intention was for a fleet of 105-mm M7 and 25-pr T51.  However, T51 did not enter service because the 25-pr Ram was preferred (probably because SPs counted as tanks under Lend Lease), and in late 1943 an order for several hundred 105-mm M7 was also cancelled in favour of 25-pr Ram (105-mm ammunition supply may have been an issue).

The Canadians produced the 25-pr Ram, so named because the SP carriage was that of their Ram tank.  Like the M7 it had an open top casemate and became the 'Sexton' in UK service. Its full designation was 'Ordnance SP 25-pr, C, Mk 2 in Mounting SP 25-pr, C, Mk 1 on Carrier, Ram, SP 25-pr Mk 1'.   More details below.  About 1373 were produced by  Montreal Loco from an order totaling 2151 for the British and Canadian (ordered and received 125) armies, production was initially slowed by lack of the M4 tank transmissions from the US, about 2/3 of the equipments were fitted with UK manufactured ordnance and mountings (Note 4) shipped to Canada.  They were used by UK, Canadian, South African and Polish regiments in Italy and NW Europe.  Sexton remained in UK service until the mid 1950's.  South Africa also retained some in Service after WW2 and some were  transferred to India.

Post war there were several attempts at a 25-pr SP.  The first in 1945 involved the hull of the CT 26 carrier and running gear of the A46 light tank, it did not get beyond paper studies.  The FV300 series of light AFVs then started development, FV304 a 25-pr SP was designed in 1947, it had a fully enclosed casemate with the gun in a barbette mount, and mock-up was produced and evaluated until 1953 when the FV300 series finally lost favour with its armoured corps proponents.  However, in 1950 a new 25-pr SP design started, FV3802, based on a shortened Centurion tank chassis.  Three prototypes were built, it too had a fully enclosed casemate and a barbette mounted gun, the barrel pointed over the engine but the drivers position was at the other end, so it was driven 'backwards'.  It was cancelled in about 1955.  
The only post war 25-pr SP that went into production (18 guns) was the Australian Yeramba, this was an open casemate design, very similar to Sexton, but was mounted on a Sherman chassis.  It  had 20° traverse Left & Right, and 40° maximum elevation and carried more ammunition than Sexton - 88 HE & Smoke, 16 AP and 118 cartridges.  Of course by the 1950's an open top SP was a bad idea due to VT fuzes.

 Q.F. 25-pr Gun Mk 2 on Carriage 25-pr Self Propelled Sexton 

Ordnance: No differences from Gun Mk 2

Mounting:                 

Elevation

 Maximum elevation of 35° reduced maximum range with charge Super to 11,000 yds on level ground [40°]

Traverse

 24° Left & 16° Right
[25° Left & 15° Right]

Carriage:

Ammunition carried

 75 HE or Smoke
 18 AP shot
 96 cartridges

On-board detachment

 5 including  driver

Wireless

 No 19 with  attached Tannoy  loudspeaker

Max speed

 25 mph (governed)

Empty weight

 22.8 tons

Length

18.8 feet [19.3 ft]

Height

 8 feet

Width

 8.9 feet [9 ft]

Armour

 Shield: ¾-inch armour plate at 23° welded to chassis and ½-inch armour plate bolted to saddle and rotating with it.  Hull; ½-inch armour plate extending 36-inches above sponson plates.

 Q.F. 25-pr Gun Short (Aust) Mk 1 on Carriage Light (Aust) Mk 1 

This gun was designed to meet the needs of jungle warfare.  It fired standard ammunition (excluding charge super).  It did not have a platform, but had 'firing segments' that supported the axle when firing.  It also had flash suppressor on the front of the muzzle because its shortened barrel meant that 'all-burnt' was outside the barrel.  It appears to have been most popular with people who did not have to use it.

Calibre

 3.45 inches

Barrel length

 14 calibres

Rifling

 26 grooves, 1 in  20 uniform twist

Chamber capacity

 151 cubic inches

Carriage configuration

 Box trail
 no platform

Elevation

Top traverse

 4° Left & Right

Loading angle

Basic Weight

 1.3 tons

Length (muzzle to towing eye)

 11.3 feet

Trunnion height

 2.9 feet

Width at wheel hubs

 6 feet

Standard HE Shell

Charge

New Gun MV

RT MV

RT Max Range

Time of Flight @ Max Range

Probable Error @ Max Range

 1

565 f/s

565 f/s

3,000 yds

24 secs

 35 yds

 1 + 1 inc

4,400 yds

29 secs

2

837 f/s

825 f/s

5,900 yds

32 secs

45 yds

2 + 1 inc

6,000 yds

24 secs

 2 + 2 incs

9,000 yds

40 secs

3

 1248 f/s

1230 f/s

10,200 yds

45 secs

 65 yds

25-pr Gun Mk 2 on Carriage 25-pr Mk 1 - a studio picture.

25-pr Gun Mk 2 on Carriage 25-pr Mk 2 - a studio picture.

25-pr Gun Mk 2 on Carriage 25-pr Mk 3 - studio pictures showing upper and lower register firing positions.

25-pr Gun Mk 2 on Carriage 25-pr Mk 1 - February 1945, a gun in action on the bank of the Shweli river in Northern Burma, probably 178 Fd Regt.  The Shweli, a tributary of the Irrawaddy, is about 300 yards wide and the town of Myitson is on the opposite bank.

No 1

Detachment Commander, move trail

No 2

Operate breech and ram shell

No 3

Layer, fire gun

No 4

Loader

No 5

Prepare ammunition

No 6

Ammunition and Fuze Indicator

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