Shortround6
Major General
See the Airacuda or B-19.
Big Guns aloft in WW2
- Thread starter SplitRz
- Start date
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This gun perhaps had potential but I believe it hadn't been perfected yet and was prone to jamming. 50mm guns had been tried on the Me 410 also I believe. One problem was the wake turbulence behind the B-17 formation which upset the aim of any precision weapons fired at long range. There were even gyro gun sights coupled with stereoscopic range finders to aim these though a stedometric unit would be perfectly adequate given that the span of the B24 and B17 were very well known. Clearly these issues had been overcome which is why it was being tried on the Me 262.
Don't forget the Piaggio P.108: per Wiki:
P.108A[edit]
P108 in flight.
In response to a request in November 1942, the P.108A Artigliere "gunship" was developed for anti-shipping duties to supplement torpedo bombers. It was armed with a modified high velocity Cannone da 90/53 gun mounted in a redesigned nose. This was considered the most effective artillery piece in service, and in several versions was used as an anti-aircraft and anti-tank gun by the Army and the Navy. To be more effective in its new role, the size of the gun was increased from 90 mm (3.5 in) to 102 mm (4 in), a non-standard Italian artillery calibre, and fired shells weighing 13 kg (29 lb) as opposed to the standard gun's 10 kg (22 lb), with a muzzle velocity of over 600 m/s (1,970 ft/s).The gun together with its recoil system weighed 1,500 kg (3,300 lb).[10] Due to it being a re-bored smaller gun, its weight was relatively low for its calibre.
The P.108A concept was in line with other contemporary developments, as medium bombers such as the North American B-25 Mitchell and even smaller attack-aircraft like the Henschel Hs 129 were being fitted with high-velocity 75 mm (3 in) guns.
The gun was mounted longitudinally in the fuselage centreline, at a depressed angle, and had a powerful recoil, which the 27 tonne (30 ton) airframe was able to absorb. The amount of ammunition that could be carried was around 50-60 rounds for the main gun, as well as up to three standard torpedoes or two radio-guided torpedoes[citation needed] (a secret weapon which was never used in combat), and for the defensive wing and fuselage turrets. The 102 mm (4 in) gun was intended to be fitted with a ballistic sight with an analogue computer, and a six or 12 round mechanical loader.[5]
Initial modifications were made to MM.24318 which on 16 December 1942 flew to Savona. The modifications were completed in February 1943, and testing commenced on 3 March.
Testing of the P.108A was satisfactory, achieving a maximum speed of around 440 km/h (270 mph) due to aerodynamic redesigning. It flew to Furbara on 19 March, and later to Pisa on 16 April, where it carried out a series of firing trials at altitudes between 1,500 and 4,500 m (4,900 and 14,800 ft) to collect the ballistic data that was required to allow the computing gunsight to be produced.[11] After totalling 24 hr, 40 min of flight and weapons trials, it returned to Albenga. It was presented as the new official attack machine at Furbara on 22 May, and it was planned to build five further P.108As, as well as converting between five or possibly all P.108s available. But on 29 June, it was decided to produce no more than five aircraft, and in July, the order was further limited to two, and eventually cancelled. On 6 and 8 September, the lone P.108A made other weapons tests over the sea, finally equipped with the S.Giorgio calibration/aiming system.[5] German forces took control of the P.108A and painted it in their insignia, but it was damaged soon afterwards by Allied bombing. Repaired by 7 April 1944, it finally flew to Rechlin where it was probably destroyed in one of the many Allied bombing raids.
Although the P.108A proved to be capable, and fired over 280 shells in testing, the Armistice and the never-ending change of priorities halted its development. The use of such large aircraft in a dangerous anti-ship role was however questionable (though the USA very successfully used B-17s to skip-bomb Japanese boats at close range & sea level) with at sea level speeds 360 km/h (220 mph) was the best safely achievable, the cost was even greater than standard bombers, and the improved naval anti-aircraft defences (Bofors 40 mm guns, P-F shells, and fire-control radar) led Germany to develop glide bombs like the Henschel Hs 293 and Fritz X.
Until the C-130 Gunship with a 105mm Howitzer, the P.108 probably carried the largest gun aloft.
P.108A[edit]
P108 in flight.
In response to a request in November 1942, the P.108A Artigliere "gunship" was developed for anti-shipping duties to supplement torpedo bombers. It was armed with a modified high velocity Cannone da 90/53 gun mounted in a redesigned nose. This was considered the most effective artillery piece in service, and in several versions was used as an anti-aircraft and anti-tank gun by the Army and the Navy. To be more effective in its new role, the size of the gun was increased from 90 mm (3.5 in) to 102 mm (4 in), a non-standard Italian artillery calibre, and fired shells weighing 13 kg (29 lb) as opposed to the standard gun's 10 kg (22 lb), with a muzzle velocity of over 600 m/s (1,970 ft/s).The gun together with its recoil system weighed 1,500 kg (3,300 lb).[10] Due to it being a re-bored smaller gun, its weight was relatively low for its calibre.
The P.108A concept was in line with other contemporary developments, as medium bombers such as the North American B-25 Mitchell and even smaller attack-aircraft like the Henschel Hs 129 were being fitted with high-velocity 75 mm (3 in) guns.
The gun was mounted longitudinally in the fuselage centreline, at a depressed angle, and had a powerful recoil, which the 27 tonne (30 ton) airframe was able to absorb. The amount of ammunition that could be carried was around 50-60 rounds for the main gun, as well as up to three standard torpedoes or two radio-guided torpedoes[citation needed] (a secret weapon which was never used in combat), and for the defensive wing and fuselage turrets. The 102 mm (4 in) gun was intended to be fitted with a ballistic sight with an analogue computer, and a six or 12 round mechanical loader.[5]
Initial modifications were made to MM.24318 which on 16 December 1942 flew to Savona. The modifications were completed in February 1943, and testing commenced on 3 March.
Testing of the P.108A was satisfactory, achieving a maximum speed of around 440 km/h (270 mph) due to aerodynamic redesigning. It flew to Furbara on 19 March, and later to Pisa on 16 April, where it carried out a series of firing trials at altitudes between 1,500 and 4,500 m (4,900 and 14,800 ft) to collect the ballistic data that was required to allow the computing gunsight to be produced.[11] After totalling 24 hr, 40 min of flight and weapons trials, it returned to Albenga. It was presented as the new official attack machine at Furbara on 22 May, and it was planned to build five further P.108As, as well as converting between five or possibly all P.108s available. But on 29 June, it was decided to produce no more than five aircraft, and in July, the order was further limited to two, and eventually cancelled. On 6 and 8 September, the lone P.108A made other weapons tests over the sea, finally equipped with the S.Giorgio calibration/aiming system.[5] German forces took control of the P.108A and painted it in their insignia, but it was damaged soon afterwards by Allied bombing. Repaired by 7 April 1944, it finally flew to Rechlin where it was probably destroyed in one of the many Allied bombing raids.
Although the P.108A proved to be capable, and fired over 280 shells in testing, the Armistice and the never-ending change of priorities halted its development. The use of such large aircraft in a dangerous anti-ship role was however questionable (though the USA very successfully used B-17s to skip-bomb Japanese boats at close range & sea level) with at sea level speeds 360 km/h (220 mph) was the best safely achievable, the cost was even greater than standard bombers, and the improved naval anti-aircraft defences (Bofors 40 mm guns, P-F shells, and fire-control radar) led Germany to develop glide bombs like the Henschel Hs 293 and Fritz X.
Until the C-130 Gunship with a 105mm Howitzer, the P.108 probably carried the largest gun aloft.
I recall a post once by someone that mentioned he knew a A-26 (or B-26) Invader gunner that told him they were able to view trucks and targets with their periscopic sight below and hit them from the top from 1000s of feet. The A-26 mechanism was a Sperry unit related to the B-29's that compensate for range, wind and motion. Obviously range was known accurately from altimeter (radar or pressure with topographic maps)
One way big guns could have been used against ground targets would be to have a ventral or chin turret armed with a canon firing downward into the thin top armour of say a tank or ship. The higher velocity 20mm guns would have worked as would 23, 30, 37 and 40mm calibres.
The key would be a computing mechanism to compensate for windage and speed . (usually just gyros to work out rates and 3D ballistic cams)
I do recall that a Heinkel He 177 variant being developed with a 30mm chin turret designed to attack US 4 engine bombers being ferried to the UK. In the madness that was Stalingrad they seem to have been used to attack armour.
One way big guns could have been used against ground targets would be to have a ventral or chin turret armed with a canon firing downward into the thin top armour of say a tank or ship. The higher velocity 20mm guns would have worked as would 23, 30, 37 and 40mm calibres.
The key would be a computing mechanism to compensate for windage and speed . (usually just gyros to work out rates and 3D ballistic cams)
I do recall that a Heinkel He 177 variant being developed with a 30mm chin turret designed to attack US 4 engine bombers being ferried to the UK. In the madness that was Stalingrad they seem to have been used to attack armour.
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The Fritz-X (1938 genesis) and to a lessor extent Hs 293 (1940 genesis) predate the war and to what extent they were influenced by the concern over radar directed guns is worth investigating. The Germans had a long history of remote controlled glide bombs going back to World War 1.
I would argue that the most powerful canon ever fitted (till something like a warthog or ac130 came along) was the Rheinmetall BK 7,5 cm used on the Hs 129 and Ju 88P simply because it was an auto canon. It had a 10 round circular magazine, fired 30 RPM. It was based on the 7.5cm PAK 40 anti tank gun.
The tsetse was clearly the most successful simply because the mosquito was so good at accepting the 57mm auto canon. Had the Ju 88 been a mid wing aircaft with a substantial bomb bay it to might have been as successful accepting the BK 5,0 and BK 7,5 instead it had a cumbersome belly pack.
Found in Wikipedia.
"According to the account of the engagements against the USAAF by II./ZG 26 from late February through mid-April 1944[4] the 53 Me 410 Hornisse of that Zerstörergruppe equipped with the BK 5 claimed a total of 129 B-17 Flying Fortress and four Consolidated B-24 Liberator heavy bombers, destroyed over five or six interceptions while losing nine of their own Me 410s"
Even if the kill claims of ZG26 are exaggerated 100% typical of claims it's still an impressive result.
I would argue that the most powerful canon ever fitted (till something like a warthog or ac130 came along) was the Rheinmetall BK 7,5 cm used on the Hs 129 and Ju 88P simply because it was an auto canon. It had a 10 round circular magazine, fired 30 RPM. It was based on the 7.5cm PAK 40 anti tank gun.
The tsetse was clearly the most successful simply because the mosquito was so good at accepting the 57mm auto canon. Had the Ju 88 been a mid wing aircaft with a substantial bomb bay it to might have been as successful accepting the BK 5,0 and BK 7,5 instead it had a cumbersome belly pack.
Found in Wikipedia.
"According to the account of the engagements against the USAAF by II./ZG 26 from late February through mid-April 1944[4] the 53 Me 410 Hornisse of that Zerstörergruppe equipped with the BK 5 claimed a total of 129 B-17 Flying Fortress and four Consolidated B-24 Liberator heavy bombers, destroyed over five or six interceptions while losing nine of their own Me 410s"
Even if the kill claims of ZG26 are exaggerated 100% typical of claims it's still an impressive result.
Admiral Beez
Captain
One round every two seconds must have been tricky to aim when you're descending towards a target.
Would the autocannon feature be worthwhile on the PAK 40-derived 7.5 cm gun on the Panther? It would reduce the crew.
Shortround6
Major General
Guys, I have tried to explain the difference between an automatic cannon and a feed device fitted to a standard semi-automatic cannon.
6pdr feed mechanism.
The RN when they fitted the guns to MGBs did away with a lot of it.
You are also dealing with the cycle rate of the gun itself.
How long does it take for the barrel the barrel to recoil and return to firing position?
this is the 6pdr
Barrel on a Pak 40 7.5cm recoiled several feet.
6pdr feed mechanism.
The RN when they fitted the guns to MGBs did away with a lot of it.
You are also dealing with the cycle rate of the gun itself.
How long does it take for the barrel the barrel to recoil and return to firing position?
this is the 6pdr
Barrel on a Pak 40 7.5cm recoiled several feet.
The gun on the Panther tank was the 7.5cm KwK 42 which had an AT version known as the 7,5cm PAK 42. It was an L70 gun. Roughly the equal of the UK 17 pounder but it was little used as a carriage mounted AT gun mainly as a tank armament. The 7.5cm KwK 40/ PAK 40 was a less powerful L48 but still enough to penetrate a Sherman or T34. The round was the same apart from the driving band.
The issue with the BK 7.5cm as a gun on the Panther would have been you would want a duel feed for HE and AT shells or some kind of carousel that could select. Perhaps in some kind of 2-3 man self propelled at gun. It might be useful as a FLAK gun if fitted with a fuse setting machine.
The Germans had settled on 5 man British style turrets. This and an efficient turret drill is why weaker armored German tanks often got in first shot first kill on nominally superior Soviet and French tanks. The extra manpower was usefull and made for a good workload. 3-4 men crews have limits. If you wanted less crew you used a StuG III or IV.
The German army had worked out that infantry assaults were often held up by the time it took to bring up artillery. It wasn't mobile and often had to be brought up at night as it was unarmored. The StuG "assault gun armoured" was self propelled artillery set into an armored tracked vehicle with strong emphasis on low profile so it could easily be hidden. A jagtpanzer was different having the full crew and operated by the Panzerwaffe instead of artillery units and tended to have more armour and fire power than a standard tank it was based upon at the expense of a turret.
The American concept of a tank destroyer was completely different to the German jagtpanzer, jagtiger, jagtpanther which means tank hunter.
the American concept was of an extremely fast and mobile gun, lightly armoured but a heavy long range gun, that could intercept and destroy at a distance and from behind cover enemy tanks that were threatening to break through.
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i get the difference. The 5cm BK-5 which is more of an autoloader weapon fired at 45-50 rpm. The far more powerfull 5.5cm Geräte 58 fired at 140 rpm and was a proper auto canon and fired on the recoil. The mechanism was based on the new 8.8cm FLAK 41.
Glider
Captain
I recognise that the thrust of the thread is WW2 but I think its worth remembering that the French Spad XII carried a 37mm firing through the propeller and a synchronised LMG in the Fuselage, with some success in WW1
Brooke
Airman
How sure are you of that? I have read evidence from first hand sources to the contrary. From "Hurricanes Over the Sands", Michel Lavigne and W/C James F. Edwards.
A.G. Williams
Airman 1st Class
- 182
- Oct 10, 2020
I don't see the word "tungsten" appearing anywhere in the page you posted.
Furthermore, in all of the decades I have been studying automatic cannon and their ammo, I have never once seen the Vickers Class S gun called the "Simeon", so I don't know where that came from. The 'S' in Class S is just a code letter for the gun, it has no meaning.
swampyankee
Chief Master Sergeant
- 3,954
- Jun 25, 2013
The Soviets tried a 45 mm gun (Yak-9K) but decided it wasn't particularly useful.
ThomasP
Senior Master Sergeant
The 'S' gun with Littlejohn adapter was trialed on a Hurricane Mk IID in 1944, per AVIA/8/857. Reliability of feed was a serious problem and the tests were discontinued.
fastmongrel
1st Sergeant
Wasn't it just a Vickers code letter like the Vickers K. It's not the official name of the gun.
Shortround6
Major General
Something doesn't add up, the first person account says soft slug in the rear of the projectile.
Tungsten carbide is hard, used for cutting tools on machines, able to cut nickel alloys and even titanium. It is also brittle and cracks/shatters with side loads.
very few people would describe a slug a metal in the base of a projectile as the 'tip'.
Tungsten carbide is hard, used for cutting tools on machines, able to cut nickel alloys and even titanium. It is also brittle and cracks/shatters with side loads.
very few people would describe a slug a metal in the base of a projectile as the 'tip'.
ThomasP
Senior Master Sergeant
The 2pdr/40mm 'S' gun APCNR projectiles fired with the Littlejohn adapter had tungsten-carbide cores. The type of tungsten-carbide used had a density of .48 lbs/in3, and was quite hard, but not as brittle as the usual tungsten-carbide cutting tools of the time. I do not know if both types of projectile were trialed, or only one.
