Heavy weight of the gun was a problem. This is why I've suggested that a more sensible weapon is made. Heavy weight meant that the gun was transfered to the artillery units, and away from the infantry units(1), the intended costumer.
Also a lot cheaper and faster to make(2).
1 + 2 meant that British were lacking the modern AT guns in 1940, and that they were using a lot of the borrowed 25mm guns.
Not sure that the British infantry was ever the customer.
A lot depends on the armies doctrine. Towed AT guns were never platoon or company weapons.
The British in 1938-1940 had lightly equipped battalions.
the Battalion had two 3in mortars total as I have said.
There were no Vickers guns, at all.
They had 50 Bren guns, 22 .55 AT rifles (if they were up to strength) and 12 2in mortars. Everything else was rifles and pistols.
Transport was 35 bicycles, 14 motorcycles, one 4 passenger car, nine 8cwt trucks, 32-33 15cwt trucks and 12-13 30cwt trucks and 10 Bren carriers.
They had gained men and rifles from 1938 to April of 1940 but little else.
British use of 25mm guns in 1940 was also a part nod to interchangeability with the French, not sure the British got a good bargain. The flimsy French gun carriages broke when towing forcing the adoption of carrying portee. Not a good solution when you are short of trucks to begin with. Not sure what the French got in exchange?
It was after France when the AA platoon was up graded to twin Bren guns in each truck and they up graded the mortar platoon to 6 mortars and 7 Bren carriers (now mortar carriers) instead of trucks.
It is not until late 1941 or early 42 that the 2pdrs arrive in the infantry battalion. But total manpower falls by 6 men. You have to redo British army doctrine, tactics, units assignements and so on to get AT guns into the Battalion's hands in 1939-40.
Whatever the tank was that the 2pdr was piercing in 1939-41, the Bohler was too. And whatever the better ammo the 2pdr can get, so can the Bohler. British can even arrange the deal so it to fires their 3pdr Hotchkiss ammo.
Money & time saved for not going with the unicorn undercarriage and a newly-designed gun can be used on making the
naval 6pdr guns also for the Army needs.
British wasted too much time, resources and money to reinvent the wheel when it is about the AT/tank guns.
Not sure where this is coming from. The Bohler is light gun and there is no magic, the gun in action was 277kg which is much lighter than the German 37mm AT gun? The HE round was fired at 250m/s.
Types of AP round are related to impact velocity, You could make a 47mm APCBC round for the Bohler but since the Bohler isn't going to hit the target at a velocity that is going to break up the uncapped shot it is just an unneeded expense/complication. British 25pdr fired a 20lb AP shot and using either APC or APCPC wasn't going to chance the performance much. US 75mm tank ammo was about the same velocity and had both uncapped and APCBC shells (In the US APCBC is called APC, they never made a capped projectile without the ballistic cap. The British made all three types). In the Sherman 75s you can see a difference and it shows best against the the two types of armor. The high velocity 2pder needed capped shot to perform well.
Saving money for the army to build coastal defense weapons is not a good trade.
To return to this.
The 47mm Bohler fired, at least in Italian service, a 2.37kg heavy HE shell. No 40mm shells will ever come in close.
The Bohler fired a much smaller cartridge case the old British 3pdr ammo and there were several different types of 3pdr ammo, a lot of it dates from the 1880s.
Information on the 1920s-early 30s 3pdr guns using some British tanks is hard to get. The Vickers are considerably more powerful than the old Hotchkiss guns but both are very overweight and neither has a recoil system as built. The British medium tanks of the 1920/30s seem to have used a new barrel and recoil system but chambered (?) for the old Hotchkiss ammo and the old ballistics. Which is why the British replaced them with the 2pd. A 3lb shot at 563m/s was not going to do the job. The 3pdr in the Medium MK II was rated at about 27-28mm at 30 degrees at 500yds. Again, these are NOT old naval guns.
The 40mm HE shell will not come close to the Italian 47mm but as I noted, it is way better than the American 37mm and it is way better than the German 37mm that was used as a support weapon in quite a number of German 1/2 tracks. Also the 37mm guns used in French tanks and the 37mm guns used in Japanese light tanks.
The British were making 2pdr pom-pom shells and were gearing up to make 40mm Bofors shells, waiting until late 1942 to put an HE shell into a 2pdr case is one of the great British mysteries.