How "should" WWII in 1940 have gone?

[CaptainCalvert]

Ideally! M3 with 1000rpm.

With only LW single seat fighters and twins as the target in 1940, .50 should be the prefered air weapon.

"With no interest now from any of the services, the .50 inch Browning again faded from the military scene. Despite this, throughout the 1930s Kynoch continued to manufacture the round and sold large quantities to foreign customers, developing a full range of loads in tracer, armour piercing and incendiary."

The US API has 0.97g of incendiary, and incendiary 2.2g, so a bit more than 0.8g. Follow on B mark IIz similar.

A 0.5" equivalent of the DeWilde inspired explosive incendiary would be very nice.
But the logic behind choosing the 20mm was that one change in gun would be better than two. At the time the decision was made, they knew the available 20mm weren't quite what they wanted and couldn't have known how long it would take to get the 20mm Hispano working so it did make sense.
On the Italian 0.5", I recall reading that it used quite a feeble round, and that this was what the RAF would have used if adopting a 0.5". The arguments against adoption - as with other 20mm - included relatively low mv, so reasonably destructive when it hit, but not so easy to get a hit. The ability to hit was a consideration when selecting 8gun (and occasionally 12 gun) batteries, and again it made sense at the time when seen as an interim fix before the 20mm became available.
Like many others, I'd have been happier to see a whole load of 6x0.5" fighters in the BoB, but the decision to stick with 0.303" made reasonable sense at the time, and once the limitations were clear, the 20mm was nearly ready - missing the tail of the BoB by weeks only.

 

[Capt Thunderbolt]

A 0.5" equivalent of the DeWilde inspired explosive incendiary would be very nice.
But the logic behind choosing the 20mm was that one change in gun would be better than two. At the time the decision was made, they knew the available 20mm weren't quite what they wanted and couldn't have known how long it would take to get the 20mm Hispano working so it did make sense.
On the Italian 0.5", I recall reading that it used quite a feeble round, and that this was what the RAF would have used if adopting a 0.5". The arguments against adoption - as with other 20mm - included relatively low mv, so reasonably destructive when it hit, but not so easy to get a hit. The ability to hit was a consideration when selecting 8gun (and occasionally 12 gun) batteries, and again it made sense at the time when seen as an interim fix before the 20mm became available.
Like many others, I'd have been happier to see a whole load of 6x0.5" fighters in the BoB, but the decision to stick with 0.303" made reasonable sense at the time, and once the limitations were clear, the 20mm was nearly ready - missing the tail of the BoB by weeks only.

Ironically, spit didn't get 4 20mm, but 2 20s and 2 .50😋

By the end of the war, bomber were introducing .50 against Harris' early wishes.

The trial of 20mm in BoB was pushed by "couch tech" RAF. When Dowding stopped the tech-heads from over talking pilots of 9 Sqn when he visited, and asked what they, the pilots wanted, the reply was they didn't work! Dowding ordered their removal.

 

[Cryhavoc101]

Ironically, spit didn't get 4 20mm, but 2 20s and 2 .50😋

By the end of the war, bomber were introducing .50 against Harris' early wishes.

The trial of 20mm in BoB was pushed by "couch tech" RAF. When Dowding stopped the tech-heads from over talking pilots of 9 Sqn when he visited, and asked what they, the pilots wanted, the reply was they didn't work! Dowding ordered their removal.

The MK XIV got the 20mm / 50 mm (Edit Wow I obviously mean 50 cal) but the later still Mk 24 got 4 x 20mm (same story with the later Seafires)

20mm made total sense however its implementation took longer than expected and in hindsight the .50 should have been adopted

IMO - but only with hindsight

 

[Capt Thunderbolt]

The MK XIV got the 20mm / 50 mm but the later still Mk 24 got 4 x 20mm (same story with the later Seafires)

20mm made total sense however its implementation took longer than expected and in hindsight the .50 should have been adopted

IMO - but only with hindsight

A good plan done in time, is better than a perfect plan too late.

 

[Cryhavoc101]

A good plan done in time, is better than a perfect plan too late.

Well they did have a good plan

Use .303 MK 2 Browning until the HS 404 20mm is operational

We here on althist.com simply want them to have a better one!

And for me that is effectively an analogous M3 .50 cal with superior explosive ammunition from 1939/40....until the HS 404 20mm is ready

 

[Draconis]

While we are on the subject my go to air gun for the early part of the war is a AN/M2 .50 using explosive ammunition

Now a .50 Browning bullet does not contain a great deal of explosive (0.8 grams compared to 13 Grams in the Hispanio explosive round) but the Italians switched to explosive ammunition in their 12.7mm Breda-SAFAT which was as I understand it a copy of the M2 Browning used in Italian aircraft and the British noticed an uptick of airframes having to be written off due to the destructive damage caused compared to that caused by solid ammunition which implies that an aircraft is more likely to be shot down by this ammunition.

This would be a good combination of rate of fire, destructive effect, size and weight as well as reliability and ease of maintenance.

If development of a 'Browning mk 3' lets call it - progresses like the Browning mk 2 (the .303 air gun) then we might see its ROF go up and weight come down in the same fashion as was seen with the British development of the MK 2.

Do you have any more information on this Italian .50 explosive round? It's an interesting concept. Though it sounds less then effective. Trading away the .50 APIs best capability, its armour piercing for an inadequate explosive charge. The slight uptick you mention may have been due to earlier versions of RAF planes without adequate fuel tank protection. Where even a weak explosive charge ignites the fuel vapours. A situation that didn't last very long.

But this is not to say the .50 round couldn't have had some potential as a HEI round. But it needs more explosive then .8 grams. Here is a brief excerpt from a Wikipedia article on how the Germans produced their 30mm HEI mine shells.

"The mine shell was made by drawn steel (the same way brass cartridge-cases are made) instead of being forged and machined as was the usual practice for cannon shells.[4]This resulted in a shell with a thin but strong wall, which hence had a much larger cavity in which to pack a much larger explosive or incendiary charge than was otherwise possible.[citation needed]"

Could the .50 bullet have been manufactured in a similar way? Thereby allowing a larger explosive filling? How much RDX could have been squeezed in? If a reasonably effective explosive charge was feasible would the Americans have fielded planes carrying a 50/50 mix of API and HEI. Perhaps negating the need for the 20mm and the problems they had with it. Of course this is all dependent on how much RDX one could put into a skinny walled .50 bullet.

 

[Cryhavoc101]

Do you have any more information on this Italian .50 explosive round? It's an interesting concept. Though it sounds less then effective. Trading away the .50 APIs best capability, its armour piercing for an inadequate explosive charge. The slight uptick you mention may have been due to earlier versions of RAF planes without adequate fuel tank protection. Where even a weak explosive charge ignites the fuel vapours. A situation that didn't last very long.

But this is not to say the .50 round couldn't have had some potential as a HEI round. But it needs more explosive then .8 grams. Here is a brief excerpt from a Wikipedia article on how the Germans produced their 30mm HEI mine shells.

"The mine shell was made by drawn steel (the same way brass cartridge-cases are made) instead of being forged and machined as was the usual practice for cannon shells.[4]This resulted in a shell with a thin but strong wall, which hence had a much larger cavity in which to pack a much larger explosive or incendiary charge than was otherwise possible.[citation needed]"

Could the .50 bullet have been manufactured in a similar way? Thereby allowing a larger explosive filling? How much RDX could have been squeezed in? If a reasonably effective explosive charge was feasible would the Americans have fielded planes carrying a 50/50 mix of API and HEI. Perhaps negating the need for the 20mm and the problems they had with it. Of course this is all dependent on how much RDX one could put into a skinny walled .50 bullet.

Only whats on the interwebs

The Italian SAFAT 12.7mm used a less powerful cartridge (12.7 x 89 - MV 765 metres per second (2,510 ft/s)) than the US .50 cal (12.7 x 99 - MV 2,910 ft/s (890 m/s) for M33 ball)

Also as Captain Thunderbolt mention on post 220 - the Browning .50 cal incendiary had 2.2g of filler - so do a sort of Dixon-Dewilde .50 cal round with 2.2 grams of explosive filler as opposed to just 0.8 on the Italian weapon.

 

[Capt Thunderbolt]

Could the .50 bullet have been manufactured in a similar way? Thereby allowing a larger explosive filling? How much RDX could have been squeezed in? If a reasonably effective explosive charge was feasible would the Americans have fielded planes carrying a 50/50 mix of API and HEI. Perhaps negating the need for the 20mm and the problems they had with it. Of course this is all dependent on how much RDX one could put into a skinny walled .50 bullet.

.50 being "small arms", usually has a copper jacket and a metal sleeve inserted with pyrotechnics. Not a lot to fragment vs a solid steel walled cannon shell (with a copper driving band)

The US "Super incendiary" M23 packed in 5.8 g of pyro mix, in '45.

The main asset of .50" is it would penetrate all aircraft armour of the time and unlike .30, smash engine blocks & wing spars.

The extra weight of cannon (and later belt feeder) in early BoB fighters caused a significant speed / climb reduction.

 

[Capt Thunderbolt]

.5 inch Vickers Blank, Explosive & Tracer
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No service blank was approved for the Vickers but before the war some development work was carried out on two types, one a conventional short rosette crimp blank and the other with a mock bullet.Little data is available on these blanks but an example of the short blank survives.Left: Unheadsdtamped experimental Vickers rosette crimped blank.Explosive

As with the blank, no .5 inch Vickers explosive round was approved for service although considerable work was carried out in the late 1930s. It is likely that this was done to increase the effectiveness of the Vickers which even before the war was considered to be obsolescent as an anti-aircraft weapon due to the speed and strength of the aircraft likely to be encountered.One form of experimental explosive was based on the design of the .303 inch R Mark III and was known as the "R" type whilst the other was of similar design to the .303 inch B Mark V base fuzed incendiary. Neither were entirely successful in trials at Orford Ness and so did not enter service. The only surviving round from these experiments is an inert mock up with a flat nosed conical bullet. It is headstamped simply "23" and has a red fibre plug in the cap chamber. It is believed to date from the late 1930s.Later, special .5 inch Vickers explosive bullets were made for proof of the lead azide pellet for the .661 inch Vickers explosive round. The .661 inch was intended to be the repacement for the .5 inch Vickers anti-aircraft equipment in the Royal Navy but was not eventually approved for service.

British Military Small Arms Ammo - .5 inch Vickers Blank, Explosive & Tracer

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sites.google.com

 

[Meester Collins]

It should have been an epic repeat of WW1 that repeats every 25 years