The Royal Artillerys Forgotten 25

Mention the number 25 to any British ex-gunner and the almost automatic response will be ’25-pounder. That venerable gun-howitzer made such an impression on the WWII years (and for decades after) that it is still foremost in the thoughts of many who served the guns. Yet there was another 25 in the Royal Artillery’s WW2 inventory although, in contrast to the 25-pounder, it did not stay very long and neither did it make a very good impression. It was a 25mm anti-tank gun and it was not a British product but French. It was le canon antichar de 25mm modele 1934 Hotchkiss.

This now almost-forgotten gun could trace its history back to 1926 when the French ordnance establishment was asked to produce a light antitank gun. The response, rolled out in 1928, was probably intended more as a design experiment to determine what might be needed rather than as a prototype weapon; at that time dedicated anti-tank guns were still in their infancy. It was a straightforward and uncomplicated design with a horse-drawn, split trail carriage providing a wide barrel traverse arc. The design came from the Hotchkiss concern of Saint-Denis (a suburb of Paris) but the prototype was found lacking. The muzzle velocity was considered to be too low and the projectile lacked the armour-penetration power the artillery felt would be necessary. (Eventually the artillery adopted a gun with a calibre of 47mm.)

Yet the 25mm project went ahead after the infantry decided that they too would need some form of anti-tank weapon. During the early 1930s the infantry arms of many European armies were investigating forms of anti-armour rifle for their infantry units, usually to be issued at platoon or company level. The French infantry staff decided otherwise, considering that a revised form of the 25mm Hotchkiss gun would be more suitable for their forecast needs and to add their own local flavour they decreed that such guns would be allocated at battalion level.

The Hotchkiss gun was therefore modified by lengthening the barrel to 72 calibres to increase the muzzle velocity to 918m/s, thus improving the armour penetration potential somewhat, and by replacing the original wood spoke wheels with pneumatic units to enable the gun to be towed by light vehicles. Other detail changes were made to the extent that the revised design was adopted for service during 1934, becoming the mle 1934. By 1935 guns were pouring off the Hotchkiss production lines at Saint-Denis to the extent that by 1940 over 4,400 had been delivered.

The 25mm guns were issued at a rate of at least two to each infantry battalion and to some cavalry regiments. Despite their pneumatic wheels most were towed by horses or mules (together with a limber for the ammunition and accessories) while in mechanised infantry and cavalry formations the guns were often carried portee fashion on halftracks. Some mechanised units were issued with CheniUettes Renault UE mlel931 light tracked prime movers.

A shortened variant of the gun was developed to arm light armoured vehicles while other examples were mounted in dismountable embrasures set into the concrete structures of the Maginot Line, the idea being that each installation could be replaced by another embrasure mounting a machine gun should the tactical situation so dictate.

The mle 1934 proved to be accurate and, thanks to a semi-automatic breech mechanism, capable of firing up to 15 rounds in a minute but once the guns started to be handled by their new owners doubts began to arise. French soldiers soon learned that the mle 1934 was an awkward load to move. Each gun and carriage weighed 480kg, to say nothing of the ammunition load and all the bits and pieces. This was just a bit too much for the usual crew of five (one of whom had to stay with the towing animal or vehicle) to handle without calling in assistance, and to add to the weight the gun proved cumbersome to move about. Not surprisingly calls were made for something lighter, leading during 1937 to another 25mm design, this time from the Puteaux concern. Weighing in at about 300kg the Puteaux mle 1937 proved easier to handle but it was apparently never a popular gun, even if about 1,600 had been manufactured by 1940.

To return to the mle 1934, during 1940 another shortcoming became glaringly apparent — it proved to be virtually useless at piercing German tank armour. The stated performance of penetrating 40mm of armour at 400m might have been adequate in 1934 but by 1940 tank carapaces had increased to the extent that the 25mm jacketed hardened steel projectiles simply bounced off their intended targets, especially when the point of impact was against angled surfaces. Despite the written statements in the manuals the projectiles proved to be too light and underpowered to penetrate anything other than the most lightly armoured targets. The projectiles used with the 25 x 194R rounds weighed just 320 grams and lacked the combination of mass and velocity on which kinetic energy projectiles depend to defeat armour.

The French were not the only mle 1934 users to make this unfortunate discovery. As early as 1939 the gun had entered the British inventory as the Gun, 25mm, Hotchkiss, Mark 1 on Carriage, 25mm, Mark 1. This adoption by the British originated as more of a Franco-British political move rather than by military necessity on the part of the British. It was the result of a pre-war gesture of Allied solidarity but in one way it was of some assistance to the British as by 1939 the supply of two-pounder anti-tank guns was still considered as inadequate to meet demands from the field and for Home Defence. The British reciprocated by passing a quantity of 0.55-inch Boys anti-tank rifles to the French.

It appears that about 220 examples of the mle 1934 were ordered for the British but there is still some dispute as to how many were actually issued to the Royal Artillery in France (the Royal Artillery were then responsible for anti-tank defence in the British Army). Most of the guns delivered went to Territorial Army formations sent to France with the BEF or to Territorial units formed or forming in the UK. According to the official Royal Artillery history of the 1939-40 period these units ‘had to make do’ with their 25mm Hotchkiss guns, which hardly indicates a ringing endorsement of their newly-acquired equipments.

Once in France the 25mm guns were organised into 12-gun batteries and carried on 15cwt trucks. Despite the usual thorough Royal Artillery preparations during the winter of 1939-40, once the fighting really started in May 1940 the 25mm guns were soon found wanting and made little impression on the attacking Panzers. Gunners did their best but the end result was that 98 examples of British-held mle 1934 guns were left in France after the Dunkirk evacuation. Guns still in the UK after that event were held only for as long as necessary or until the limited stocks of 25mm ammunition ran out following training.

As soon as sufficient two-pounders had been delivered to the Army the remaining 25mm guns were retired. More came into the British fold following the 1941 campaign in Syria — those trophies were passed to the Free French and the Polish Brigade. Perhaps the largest users of the mle 1934 after the Fall of France were the German armed forces. So many intact 25mm guns fell into German hands, along with stockpiles of ammunition, that they had to be utilised in some manner or another, even though it was appreciated that the mle 1934 was useless as an anti-tank weapon and there was no 25mm high explosive round to utilise. Apart from three types of armour-piercing ammunition, plus inert and drill rounds, the only other nature ever produced was a low power training round.

Even so, the German victories of 1940 meant that garrison units based in the newly occupied parts of Europe had to be equipped with weaponry, no matter how inadequate it might have been in its intended role. Renamed as the 2.5cm PaK 112(f) the mle 1934 was issued to static or garrison units to act as coastal battery perimeter defence weapons or in anti-invasion strong points, and other such functions. When the end came in 1945 many of them were still around, still held as not very effective infantry guns.

After 1945 most surviving examples of the mle 1934 appear to have been fed into scrap furnaces but a few survived to end up as gate guardians or in museums, some as far away from France as Finland (another 1939 recipient of French largesse) and Romania (via Germany). A few also appear to have ended up in private collections so it is still possible to encounter reminders of a WWII gun that is now almost forgotten, even by the Royal Artillery.

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