WWII aircraft armament machine guns and cannon

[105kw]

FWIW, the B-52s that went to Vietnam were mostly D models.
They could carry more 750lb bombs than the H models, and had 4, 50cal, radar aimed guns in the tail. The H's had a 20mm Vulcan, and were used as SAC bombers exclusively.

[davidsog]

FWIW, the B-52s that went to Vietnam were mostly D models.
They could carry more 750lb bombs than the H models, and had 4, 50cal, radar aimed guns in the tail. The H's had a 20mm Vulcan, and were used as SAC bombers exclusively.

One of most awe inducing events I ever witnesses was an Arc Light, at night, in the First Gulf War during the bombing campaign.

[44 AMP]

Played with rough numbers, a fired .50 BMG case weighs about 2 ounces, falling from a B-17 cruising at about 180mph, striking another B-17 cruising at about 180mph will have somewhere around 150ft/lbs or energy +/- due to variables.

My guesstimate is that would be enough to tear a hole in the skin of an aircraft, even a B-17.

[davidsog]

My guesstimate is that would be enough to tear a hole in the skin of an aircraft, even a B-17.

[RC20]

Yea, NASA should have done that calculation on the Space Shuttle, may they rest in peace.

Some interesting data sets that if the Brits had left the gunners at home, their losses would have been hugely less as their defense in the dark was very poor (not to mention the stupid 303 guns)

Occurred to me, strip the B-17/24 of all armament, leave gunners at home, gain speed and altitude.

Yes you would have the losses, but a lot fewer people down (killed or jumped and prisoners) and what would you have gained avoidance wise by higher speed and altitude?

Once the fighters knocked out the Luftwaffe, you did not need the guns, leave all that at home as well.

The military mindset is pretty strange. The AWACs that went down in Anchorage on bird strikes was fully personed and all it was doing was touch and goes.

But, you will fully person it any time its flying. So we lost a large number of lives for zero gain not to mention them grossly ingraining and doing nothing about the bird issue. They tried to blame a sergeant who had something like 15 assignments, last priority was bird control and no resources to do it with.

Brave women and men doing their duty let down by the highers almost always

[RC20]

The Battle of Britain Spitfires and Hurricanes carried enough ammo for about 20 seconds of firing time. Green pilots everywhere tend to shoot themselves dry frequently. "The Few" of RAF fighter command saved Britain, and became national heroes. Because of that, the errors, flaws, and failures have been largely under reported, glossed over, or even outright ignored by historical accounts written afterwards. Also, don't forget the influence of propaganda (and pride) influencing what has been written.

The .303s in RAF fighters wings were NOT "crappy guns". They were excellent guns mechanically, being a variant of the Browning 1917 machine gun, made by Colt for the RAF, and any lack of effectiveness needs to be laid at the feet of RAF command and their decisions, not the gun, or the cartridge.

Ok, you are splitting hairs. The 303 was an is a crappy cartridge in the context of cartridges. Its dated, poor velocity and rimmed. So yea, its a crappy cartdige.

The guns were the wonder of the world. Fantastic gun shooting a crappy cartdige let alone a 30 caliber (30-06 was no better) - so yea, it sucked.

And, you are ignoring ineffective. A 2 second burst of 50 cal on target took out the target. 10 seconds of 303 put some holes in it.

There are some tables on effective of rounds. The most recent was 20 mm and it took 5 or 6 hits to take down a bomber.

30 mm took one or two.

Where the 50 cal shined was lots of rounds, effective rounds and plenty of time firing. Kill more targets, finish off a target.

And its also situational. 50 cal worked for the US and in context of huge numbers of not necessarily natural aviators (aka shots). But you also had enough seconds of firing you could adjust on the fly and actually learns something on shooting and effective.

You will note that most US went to 50 cal for applications over 30 cal and some like the Dauntless had two forward firing 50 cals.

Yes the rear armament was 30 cal, but that was a discouraging setup, best replaced by one 50 cal but in theory you had fighters to help you out and it was just enough to discourage an attack or make it nervous.

Japan used a fair amount of 20 mm defensive cannon because their aircraft operted sans fighter support.

[44 AMP]

Occurred to me, strip the B-17/24 of all armament, leave gunners at home, gain speed and altitude.

Yes you would gain some. Think you would gain enough to ensure bomber survivability?? I seriously doubt it.

The B-17 cruise speed was about 180mph, max speed is listed as 250-287mph (depending on source and specific model) and the plane could not maintain that speed for very long. SO, how much speed increase (particularly sustainable speed) do you figure you'd get by removing all the guns, and 60% of the crew?

Think you'd be as much as 50mph faster? 80?? even if you got that, you're still much slower than the fighters trying to kill you. AND defenseless.

US heavy bombers were carried the heaviest defensive armament of any common bombers of WWII. And even flying in tight formations where the fire was mutually supporting, without fighter escorts in contested skies, we still lost a LOT of planes.

Look at Black Thursday for the worst example. 299 B-17s attacked Schweinfurt, without fighter escort and with full defensive armament. 60 were shot down. That's about 20%. How much higher do you think the losses might have been even with faster bombers, without defensive armament?

[Pumpkin]

I remember reading somewhere about Luftwaffe pilot’s be asked which Allied heavy bomber they would not want to engage the most, the B-17 was the one they picked.

[44 AMP]

Ok, you are splitting hairs. The 303 was an is a crappy cartridge in the context of cartridges. Its dated, poor velocity and rimmed. So yea, its a crappy cartdige.

I am splitting hairs because you are twisting so many together its clogging the filters.
I was referring to a specific point in the war, the summer and fall of 1940, what the combatants had, at the time, and what they did with it. Valid points that happened in 41, 42, 43, 44, and even 45 simply do not apply to what happened in 1940.

The guns were the wonder of the world. Fantastic gun shooting a crappy cartdige let alone a 30 caliber (30-06 was no better) - so yea, it sucked.

All the rifle calibers used by the major combatant nations were fairly close in performance, firing bullets of 30-32caliber within about 300fps of each other, or less. So, ok, they sucked, compared to the .50s and cannon that were in use a year, or two, three, and four years later

And, you are ignoring ineffective. A 2 second burst of 50 cal on target took out the target. 10 seconds of 303 put some holes in it.

There's no question the 8 gun .303 fighers were not as effective as they could have been, and should have been in the early stages of the Battle of Britian, but they got better significantly after squadrons under Tuck, Malan, and Bader "showed the way" by discarding offical RAF standing directives about gun regulation and ammo used.

Considering that the Luftwaffe admits to losing over 1500 aircraft, the majority of them to RAF fighters, I wouldn't say the .303 was ineffective at that time and place.

Later on, better and more effective things were available, absolutely, and when they were, the rifle caliber only armament was rapidly replaced.

There are some tables on effective of rounds. The most recent was 20 mm and it took 5 or 6 hits to take down a bomber.

Right, and what are the tables based on?? Average results compiled from
the entire war?? What bomber(s)?? There is a huge difference between a B-17 and a Mitsubishi G4M "Betty" for example.

There are many, many factors involved, more than just the cartridges used, and I think it is important to consider things like the time, place, aircraft used, amount of aircraft engaged, tactics, over all pilot skills (training) and other things, not just overall totals of results. What worked in 1940 is drastically outmoded in 1944. Roll all the different "epochs" of WWII air combat together and you get distorted generalities, not accurate history.

[RC20]

Think you'd be as much as 50mph faster? 80?? even if you got that, you're still much slower than the fighters trying to kill you. AND defenseless.

Taking this as a sole item, I don't think you understand aerial interception. Say the B-17 could get 300 mph by dumping all the guns, ammo, gunners and armor.

If the German system allowed a pre position, you get one pass, then you are falling behind at 300 mph.

So your fighter goes 360 mph. You now have a slow closure rate, Ok, lets keep the rear guns and gunner. Do you really want to fly up the tail of 20 B-17s in a formation? No

So, you go left, loose more over take, then you go up so you can do a fast dive, and then, you are out of fuel.

So yes, speed changes the dynamics. Its an interesting discussion because it uses math to balance against the knee jerk of just put more and more guns and more and more armor on it.

The ultimate was the B-17 escorts which was a failure (forget if it got combat or now)

AAC would not even think it, after all, it was run by the Bomber Mafia at the time that would not let the P-47 have drop tanks to allow escorts and avoid Black Thursday.

[44 AMP]

So yes, speed changes the dynamics.

It certainly does.

There is quite a difference between when your top fighter speeds are in the 350pmh range (Battle of Britain) and 4 years later over Europe when the top fighter speeds were in the 450mph range. or higher when the jets showed up.

With the engines they had, I don't think you could get 300mph lightened and streamlined by removing the guns and their turrets. Not as anything other than emergency over boost. And even if you could, you can't fly long at that power setting. With different, significantly more powerful engines (and with the bugs worked out of them) MAYBE....

The B-17 gunships were a failure, primarily because they were so heavily loaded they couldn't keep up with the bomber formations, so they couldn't "hide" in the bomber stream to ambush attacking fighters.

The only B-17 gunship combat I can think of off the top of my head happened in the Med, the attacking fighters thought they had a straggler..and got quite surprised. I'll have to check on the details, no longer remember them directly. I do remember that it only worked once, after that, the enemy was on the lookout for the gunships.

The P-51 gets the glory in the popular press, and had longer range on internal tanks than earlier fighters, but P-47s and P-38s could get to Berlin and back with drop tanks, it was command decisions, NOT aircraft capability that handicapped them. Once the Mustang (D model) showed up the people running the 8th AAF pushed the Thunderbolts and Lightnings out (over pilot protests), and sent them to the 9th AAF in the ground support role, keeping only the Mustang as their air superiority fighter escorting the bomber formations.

Looking at the history of the air war (and the entire war in general, as well) you see many, many instances where we had adequate or even superior equipment to do the job, but were handicapped by what the brass wanted, instead of using what we had to its fullest effectiveness.

[Pumpkin]

Would the B-29 been a prime example of this because of it not being used in Europe?
I believe it entered service about 1 year before Germany surrendered.

[44 AMP]

The B-29 had a listed cruise speed of 290mph, and max sustainable speed of 354mph with a maximum speed of 380mph at 25,000 ft and 408mph at 31,000 ft, depending on which source you read.

The agreed on first combat use seems to have been 5 June 1944, bombing Bangkok.

[Mike Irwin]

The B-29 was not used in Europe primarily due to the need for a bomber with the range capable of striking Japanese targets from the bases that were then available.

American heavy bombers like the B-17 and the B-24 simply didn't have the range required. They could hit forward targets, but that negated their ability to serve as strategic bombers.

That wasn't nearly the problem in Europe, where Allied bases in England were capable of getting to just about any target in Germany or German-occupied Europe.

So, realistically, no really operational need for the B-29 in Europe.

[105kw]

My uncle told me that by June 1944, the Allies had air superiority over Europe.
His next comment was " Somebody should've told the Germans."
The Luftwaffe was looking for a working 30mm, because it could take up to 30+ 20mm hits to disable a B-17 or B-24.
To minimize defensive fire, the Luftwaffe went to head on attacks, at a very low angle dive.
After blowing through the formation, they would regroup, circle back and reposition for another attack.
When our fighters started escorting all the way to target, it got harder for the Luftwaffe. But they never did quit trying, we were bombing their homes.

[RC20]

So, realistically, no really operational need for the B-29 in Europe.

I would put it somewhat differently but the end result is the same. By the time the B-29 could have flown European missions, they were on the German border. B-25 and B-26 could fly missions anywhere in Germany.

But the B-24 and B-17 had the range regardless. Frankly I don't know they ever moved the bases for those out of the UK. Fighters yes for all sorts of reasons but a bomber base is vastly harder to move and for no gain.

My uncle told me that by June 1944, the Allies had air superiority over Europe.
His next comment was " Somebody should've told the Germans."

While valid if you are the aircraft that got shot down, in the main, it was no longer a issue. Losses to the Germans were low at that point, not non existent.

Equally I had a friend who was a radio operator in that latter period and his comment was flak was the biggest issue, very little airborne opposition. His aircraft was never hit.

Luftwaffe did have a working 30 mm cannon and its only issue was getting close and time to use them.

Head on attacks were not the norm. Some good U Tube out there on how it was tried and then discounted. Keeping in mind a lot of factors, but one was you wound up way behind the B-17s. If you wanted to do another head on attack you had to recover, turn, get out of side range of the 50 cals and then forge ahead, gain altitude and only then could you repeat.

I don't remember what pattern was preferred in the end but it was side or top of some kind. Coming up from low you were a sitting duck.

[RC20]

Right, and what are the tables based on?? Average results compiled from
the entire war?? What bomber(s)?? There is a huge difference between a B-17 and a Mitsubishi G4M "Betty" for example.

I should have been clear but a G4M would not have been a 20 mm target (maybe in some extreme cases at the very end when the Brits were operating in the Pacific, possible but barely for some late Corsairs off Okinawa.

[RC20]

There are many, many factors involved, more than just the cartridges used, and I think it is important to consider things like the time, place, aircraft used, amount of aircraft engaged, tactics, over all pilot skills (training) and other things, not just overall totals of results. What worked in 1940 is drastically outmoded in 1944. Roll all the different "epochs" of WWII air combat together and you get distorted generalities, not accurate history.

For the US it was 50 cal all the way, so frankly you can use that as a base of comparison to what was going on around that.

I have not seen any citation of Brits and different gun setups being a major factor. The Reality was a lot of German Aircraft got shot up and got back to France. If all you have is 8 x 303, you use it, but its a compensation for being inferior. Some US fighters started the war with 4 x 50 cal and some continued that as a choice (and the Jeep Carriers for land support it was mainstay for that Wildcat (as I recall).

Japan, Germany and the UK all recognized that a 30 caliber was not particularly effective against a modern fighter with trained pilots (aka not China or Spain) and it was a constant effort to up-gun.

So they jumped to 20 mm and even 30 mm. Brits recognized the 303 was not particularly effective against even a twin bomber. They could have gone for a 50 cal solution (and some Spitfires did have that in the combo armaments)

Japan and Germany had the reality of B-17/24 and Lancaster that the 303/321 cals too far too many hits to take down. So going to 20 mm was natural over a 50 cal solution.

There is not question that the US held out because they could, the target set never justified a shift over though the USN was working in that direction.

USAF went with 50 cal in the F-86. The 20 mm was probably a better choice but only if it worked and the USAF and the USN had issues making 20 mm work (which sounds stupid). Europe moved in the direction of revolver cannon in 30mm.

The US went through WWII with the M4 Sherman. Not because it was the best (though far from as bad as many think) but simply changing had major downsides and it was good enough for what was needed.

Individually like 105kw Uncle you would find crew that had Panther envy. But then a Panther crew with a broke down tank had Sherman envy. Dang, there is always a 100 of them and they are all running!

The M4 reality was that if you look at crew losses, they were extremly low. I believe under 2500 in WWII. It was not that the tanks did not get shot up and a mission kill, but the crews tended to get out and there always was another tank ready for them (often a repaired). Some of the Normandy radial models were still operation when they got to the Elbe River and it all stopped.

Now, 30mm revolver cannot the norm for Europe, US uses a 20 mm gattling gun (though the F-35 has all of 2 seconds worth of full on firing) and the Russians a 30mm recoil cannon.

Me? I would rather have 6 or 8 50 cals with a lot of firing time vs a 20mm cannon with limited firing time.

[44 AMP]

The M4 reality was that if you look at crew losses, they were extremly low. I believe under 2500 in WWII. It was not that the tanks did not get shot up and a mission kill, but the crews tended to get out and there always was another tank ready for them (often a repaired).

I suggest you read "Deathtraps" by Belton Cooper. Its about his time as a vehicle (primarily) Sherman recovery officer.

When the DAK met British crewed Shermans in Africa, they nicknamed them "Tommy cookers". US tank crew losses in Europe vastly exceeded expectations, to the point where virtually untrained replacements were put into tanks, got to fire a few rounds, maybe, as training, and then sent into combat, with entirely predictable results. If total deaths were as low as you claim, I'd say that is more a testament to our medical service than the M4 or the way it was crewed and used.

Getting back to WWII aircraft armament, its important to consider both what combatant nations had, and how they chose to use it, and also that there were times when the combat pilots seriously disagreed with the military and political choices.

Japan and Germany had the reality of B-17/24 and Lancaster that the 303/321 cals too far too many hits to take down. So going to 20 mm was natural over a 50 cal solution.

The Luftwaffe put a pair of 20mm cannon in the 109E models beginning in 1940, The Japanese Zero was flying combat in China with 20mm cannon at the end of 1940. The RAF began putting 20mm cannon in numbers in Hurricane and Spitfires in 1941. And in 1941, the Luftwaffe got the 109F which had LESS armament than the E models, going from 2 cannon and 2mgs to one cannon and 2 MGs. And, at the same time, the primary US fighter, the P-40 had a pair of .50s in the cowl, and a pair of .30s in each wing. And the FW 190 showed up in 41, with two 8mm cowl guns and a pair of cannon in each wing.

The US navy's F4F-3 had 4 .50s in the wings, and its "upgrade" was the F4F-4 which had 6 .50s, but less ammo per gun, something many pilots objected to.

And the fleets of B17s and B24s didn't reach Germany until 1943. The RAF's night bombers were rarely engaged by single seat fighter aircraft. The Luftwaffe night fighters carried a mix of cannon and mg armament.

The auto cannons developed post WWII for the jet age are a different topic, one that does not apply to what was used in WWII.

[Pumpkin]

I still have a book from my childhood called “Night Fighter” that gives a true account of radar equipped Bristol Beaufighter night fighter in WWII.
In one chapter it describes the difficulty that the radar operator had changing out the empty 20mm drums while engaged in shooting down a Ju-88. Additional armament on that plane was 6 .303 guns in the wings. Having the ability to recharge the cannons had to be a welcome feature not always available on other fighters although it was a big old bird.

Quick note:
One thing to consider about the American tanks was they ran on gasoline.
This made the chance of a deadly fire in the crew compartment was much worse than the diesel powered German tanks. Wasn’t it given the Sherman nicknamed Ronson after the lighter?

[Mike Irwin]

Yes, B-17s and B-24s were based in France after D-Day. To what degree, how many, for what primary purpose I've not yet ferreted out.

[Mike Irwin]

Belton Cooper is an interesting, and rather divisive, narrator of the Sherman story.

Some of his claims in his memoir have been contested by historians, in some cases with significant documentary evidence to counter Cooper's claims.

The entire concept of "tommy cookers" or "ronsons" can be divided into two phases...

Pre January 1944 and post January 1944.

January 1944 saw new Shermans equipped with wet ammo storage. This also included retrofit packs for in-service Shermans.

Wet stowage reduced the potential for a hit detonating the main gun's ammunition stores by upwards 90% over tanks without the wet storage.

That obviously didn't help those British and American crews who had used the Sherman in combat in Africa, but total combined forces uses of Shermans in Africa was, from what I can find out, was likely fewer than 1,000.

More Shermans were used in Italy but again, I'm having trouble finding out how many.

In both theaters, Shermans suffering hull penetrations could "brew up."

But here's an interesting fact that no one ever seems to mention...

First, in Africa and, to a degree in Italy, the Sherman was well matched against German tanks that were on the ground and completely outclassed Italian tanks.

The primary threat to Shermans in both theaters was heavy German anti-tank guns, primarily the various 75mm and 88mm guns, but the 40-50mm guns could also take a toll.

Second, and this is something that people who deride the Sherman as Ronsons or suppliers of prime "Charred British Beef" is that German tanks were equally likely to "brew up" because they didn't have wet storage, either.

Finally, the M26 Pershing... would it truly have been the panacea to all of the Sherman's ills?

Well, yes.

And most emphatically, no.

The Pershing would have been better matched against German tanks in terms of firepower... but the performance of the 90mm gun and its ammo still lagged significantly behind the long-barreled 75 and 88mm guns on German tanks later in the war.

So that alone would not have leveled the playing field to any significant degree although the 90mm was a leap ahead of both the 75 and 76mm Sherman guns.

Worse, and what most people fail to consider, is that the Pershing's armor wasn't much, if any, thicker or better than late war Shermans (and it was significantly lighter than the armor on the Sherman Jumbo assault tanks), which realistically meant that the M26 would have been just as vulnerable to German tanks and AT guns as the Sherman was.

Finally, there's one last problem with the M4 vs M26. The M26 was significantly heavier than common Sherman variants (the Jumbo was almost as heavy as the M26) but worse, it was dimensionally larger, meaning that getting the M26 across the ocean to the battlefield was going to be a greater challenge.

One claim I read some years ago was that roughly half the number of M26s could be transported using the same resources -- so if you could fit 100 Shermans in a convoy of 10 ships, you were only going to get about 50 M26s in the same ships.

So, while I think Belton Cooper's claims do have some merit, I don't (and many others don't) believe that they offer a full view.

[Mike Irwin]

"Quick note:
One thing to consider about the American tanks was they ran on gasoline.
This made the chance of a deadly fire in the crew compartment was much worse than the diesel powered German tanks. Wasn’t it given the Sherman nicknamed Ronson after the lighter? "

What did all of these German tanks have in common?


Panzer I
Panzer Mk II
Panzer Mk III and variants
Panzer Mk IV and variants
Panther and variants (e.g. Jagdpanther)
Tiger I and variants (e.g. jagdtiger)
Tiger II

They were ALL fueled by gasoline.

Every single one of them.

All German tanks, and I'm pretty sure that all of the armored assault vehicles and self-propelled guns were also 100% gasoline fueled.

I've heard many times over the years that German tanks didn't "brew up" like American tanks because of the diesel engines. But it's simply not true.

The Germans tried to develop a diesel engine for armored use, but it was a failure.

[Pumpkin]

Ouch!

[Jim Watson]

As a co-op student and junior engineer, I worked with a lot of WWII and Korea veterans.

I don't know the timing, but I had a project manager who was a B24 bombardier based in Italy.

We had another engineer who got out of a hit tank but not intact; he lost an arm. I don't know if his limp was due to a lamed or missing leg.

It seems that every ETO GI was morally certain that he had been routinely shelled by the German 88 as though they had no other cannon.