It would have been easier to harmonise the brownings to have the inner four shoot within a 1 meter box at 200 meters and the outer four the same at 250, ditch the Mk VII ball, it was designed to shoot deer not aircraft, have the belts with two AP, two incendiary and the fifth a tracer. The Hispano and it's ammunition have a lot of ironing out to get the reliability up to an acceptable standard so are a no go for the BoB so use what you have, eight RMG's sighted to give a higher concentration of fire onto a given point with more effective ammunition.
WW2 bombers. If Germany had the allies heavy bombers would they have won the war?
- Thread starter Readie
- Start date
It would have been easier to harmonise the brownings to have the inner four shoot within a 1 meter box at 200 meters and the outer four the same at 250, ditch the Mk VII ball, it was designed to shoot deer not aircraft, have the belts with two AP, two incendiary and the fifth a tracer. The Hispano and it's ammunition have a lot of ironing out to get the reliability up to an acceptable standard so are a no go for the BoB so use what you have, eight RMG's sighted to give a higher concentration of fire onto a given point with more effective ammunition.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Chances are, the exact same thing will happen to the Luftwaffe's heavy bombers as happened to their medium bombers historically.
The Luftwaffe's inability for the escorts to communicate with the bombers and the escorts short range was the German's Achilles Heel and cost them the needed success in their offensive.
No German bomber was well defended and the B-17/B-24 loss rates shows that even the war's heaviest armed bombers were dead-meat without a solid escort.
The Luftwaffe's inability for the escorts to communicate with the bombers and the escorts short range was the German's Achilles Heel and cost them the needed success in their offensive.
No German bomber was well defended and the B-17/B-24 loss rates shows that even the war's heaviest armed bombers were dead-meat without a solid escort.
There is no evidence for that that, larger rounds are far less disturbed by air currents. The Ikara MG FF (basically the Oerlikon with the shorter medium velocity cartrige) weighed only 23kg and was successfully used on hand swivel mounts on a number of Luftwaffe aircraft as was the MG151/20. MG FF (and MG151) found themselves on swivel mounts on the nose of the He 111 and Do 217 and rear canopy of Ju 188.
The MG15 fired 1050 rpm of rifle calibre bullets from a 75 round magazine. A 4 second burst with say 5% hits would put about 4 rifle calibre rounds weighting 12.7 grams into a target.
The MG FF fired 540 rpm of 20mm bullets from a 60 round magazine. A 4 second burst with 5% hits would put about 2 x 20mm rounds weighing 134 grams in to the target.
If a 12.7 gram bullet hits a Hurricane bullet proof widescreen it gets scratched. If it hits an oil cooler or radiator the engine looses power 5-10 minutes latter.
If a 20mm bullet hits the windscreen the pilot dies or gets injured enough to make him loose interest. If it hits the shank of a propeller blade it gets blown of, if it hits the engine block it starts leaking oil and stops working.
Luftwaffe fighters sometimes had no more than 5 minutes over Britain and never more than 15 minutes. Drop tanks mean they turn up at high altitude near the UK coast with a full tank of internal fuel having used the jettison tank to form up, gain altitude, find the bombers they are escorting and cruise. The ammunition problem is over stated, 60 rounds at 540rpm is 11 seconds which still leaves plenty of (30-45) seconds of 7.92mm from accurate central guns. If you assume an Me 109E4 has an range of 400 miles its operational radius will be 1/3rd of that which is 133 miles. With a drop tank the range goes to around 650 miles and the operational radius goes to about 220-240 miles. The bombers are much safer, the Hurricanes and Spitfires take greater losses.
The 20mm MG FF was in service but the 40% faster firing higher velocity MG151/20 was not. The 20mm tail gun on the He 177 had about 55 degrees swing to either side if the tail gunner was in the prone position or about 30 degrees if he chose to sit. Glass looks optically clear, nice and flat and bullet proof.
The Hispano was not yet ready by the BoB and was particularly finicky in wing installations (OK in mosquito).
The rear gun on the He 177 was effective:
P-61 Black Widow vs. He 177 Greif (spoiler alert happy ending)
FalkeEins - the Luftwaffe blog: P-61 Black Widow vs. He 177 Greif
The proposed armament for the Do 19 and Ju 89 when they flew in 1936 on miserable 600hp engines was twin 20mm guns in the dorsal and ventral bathtub (presumably forward and rearward facing)
The MG FF and MG FFM could use 30,45,60,90 magazines and I think the 30 could come as a clip or drum. Choice of magazine seemed to depend on installation (nose, ventral bombola facing forward etc). I know the 90's were for the Fw 190 but pictures suggest both 30 and 60 were used on Luftwaffe aircraft in flexible mounts. It would depend on the space available.
"and not been a whole lot better armed than the twin engine planes" Yeah, sure, you are serious. A hit by a 134 gram 20mm bullet is likely to be devastating to a pilots bullet proof wind screen, engine block or propeller shank whereas a 12 gram 7.92mm round will likely do next to nothing other than a 20 minute repair. The rear guns, even if only a MG15 at least got a very clear shot at the approaching fighter and likely would have been a 20mm gun by 1939/40. Both the MG131 and MG81 were in production by 1940.
RW Mk. III
Airman 1st Class
This is all quite true. But so is GrauGeist's point about the USAAF's experience. The defensive armament of a bomber, no matter how good, is not going to substitute good or better fighter cover.
The 4 engine bomber/higher altitude bomber/better armed bomber is misdirected resources in my opinion. The Germans would have been better off to just use 111's as they were. But develop more range into the 109, and better communication and tactics for escorting bombers. The easiest way to get the technological edge to win the BoB is improving fighter cover. Heavier bomb loads are great for strategic bombing, but Sealion (the feasibility of which is a whole seperation discussion) needed air superiority. The smaller two engine bombers were if anything, better suited to the tactical bombing requirements of the strategy. Flatten the airfields, then support the landing force as it crosses the channel, then support troops on the ground. Thus was right up the LW's alley as-equipped. But the air space was far too contested.
Glider
Major
Nice example but the angle of fire with a drum loaded 20mm would be far less than an LMG plus the poor ballistics of the FF would significantly reduce the chances of a hit. I think you are also losing sight of the main aim of the bombers guns. The primary objective wasn't to shoot down the fighter, it was to stop the bomber being shot down. Your LMG hitting the windscreen would seriously craze it and almost certainly the fighter pilot would pull away, job done. It was very unusual to continue attacking a bomber once you have started to take hits.
The statistics of the He177 are interesting but it wasn't a drum fed FF cannon, you would be lucky to get 20 degrees.
Maybe the fall of France took the LW by surprise as much as anyone, did anyone believe that they would be in a position to attack the UK in 1940 until they actually were.
Shortround6
Lieutenant General
fixed and where the Luftwaffe put MG 151 cannon on later bombers is only of moderate interest in 1940.
Tony Williams says 11.5 grams for an AP bullet. Maybe he is wrong. Maybe 12.7 grams is for a lead cored bullet used in ground guns?
Here is where things start getting strange. Mathematically you are correct. Except the flexible 20mm MG/FFs guns seldom used a magazine that allowed for 4 seconds of fire. Both 15 round and 30 round magazines were used. 4 seconds at 9 rounds per second (540rpm) is 36 rounds.
No, 540rpm from a 60 round ammo supply is 6.66 seconds.
Early He 177s used an MG 131 in tail with a smaller tail cone and no raised top for sitting position.
Here we run into limits of traverse of the mount and practical limits imposed by airflow and the gunners muscles/body mechanics. Most countries finally figured out that trying to fire more than 45 degrees to the fuselage was not possible with any degree of accuracy as the gunner was spending so much effort fighting the slipstream on the barrel/s.
Granted this is a generality, but you have about 4 basic position for the gunners. Standing with feet on floor or braces, gunner can use his body and leg muscles to help gross aim the gun while using the arm/should muscles for fine aim. Seated upright position, a bit less movement of the body, and bit less leverage for the legs, gunner can still twist in seat or swivel.
Seated on floor or kneeling. Leg muscles and movement are pretty much out of it. Upper body from waist up? shoulder and arm muscles doing more of the work. Laying prone with chest on pad. Now we are down to pretty much the shoulder and arm muscles. arms are out over the head and the head itself has a limited range of motion to stay lined up with the sight.
Add to this the bigger the barrel the more area the slipstream has to push against. A long barrel is worse than short barrel due to leverage but a short fat barrel and spring housing/sight has a lot of "sail" area.
Granted this is the nose gun of a He 111 but you get the idea compared to a MH 15.
I don't much care what was proposed. The British were proposing quad 20mm turrets and single 40mm turrets before the war.
To me what matters is what was used at the time in question or very shortly (a few months?) after.
AS above, what was the Luftwaffe actually using in service aircraft in the summer and early fall of 1940? Most people that support this idea of German 4 engine bombers want hundreds of bombers (production had to start in 1939, but want them ALL equipped with the lastest, greatest guns, engines and equipment from the last week of the campaign.
So yes I am serious.
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As has been pointed out, these positions would have been manually operated in 1940 - the Germans did not have a workable power turret at the outbreak of WW2 and did not install such a thing in an aircraft until the maritime patrol variants of the Fw 200 in late 1940/1941. As it was proposed, the Ju 89, by 1940 is not a very potent machine and the RLM was best sticking to the twin engined bombers they chose, rather than the four engined heavies it had planned before the war. The Do 19 and Ju 89 were singularly unimpressive and would not have offered anything more than what the LW had available in the BoB, except that the LW would have had fewer aircraft available. Also, there's that perennial argument that LW fanboys always ignore; if Junkers puts the Ju 89 [or insert favourite aircraft of choice here] into production, what is it not building in quantity that it probably needed?
Establishing a production line for big heavy bombers is a massive undertaking and requires enormous resources, space and labour. Yes, Junkers had built big aircraft before, but on a production line like what it was doing with the Ju 86, Ju 87 and Ju 88? Never. It took the British vast amounts of time, space and effort to going from building the likes of the Handley Page Harrow and Hampden to the Halifax, then from the Avro Anson to the Manchester/Lancaster.
Sure, with better engines, better defensive armament, the Ju 89 might have been a headache for the RAF, but I doubt it. It was slow, poorly defended and had a pitifully small bomb load for such a big aeroplane. Again however, the outcome would probably not have been much different. The Germans lost the Battle of Britain NOT because of the types of aircraft they operated, but they never were able to quantify the damage being done to their targets - German reconnaissance aircraft got intercepted and shot down, and reports from fighter pilots of RAF losses were exaggerated and unfortunately the LW hierarchy believed what they were being told and then based their strategic decision making on false information. The Germans had no real perception of what they were achieving, or not as the case was. That's not going to change with four engined bombers.
This is the part of the argument that always rears its head with these sorts of discussions, as I've pointed out before. "The [insert aeroplane type here] WOULD have been better than anything the Allies had, IF it received the more powerful engines [insert scenario that actually took place that the aircraft in question's designers had no control over]" The Bomber B programme and the aircraft built to it were destined to delay and eventual failure because the Germans could not develop the engines they wanted for them.
Pretty much. You can't hinge an argument's success on something that was promised but never took place.
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And
It has nothing to do with air currents and everything to do with trying to hit something flashing by you doing hundreds of miles an hour.
Park would continue his pealing away the fighters tactic so the deeper into England they go the more units they are engaging, you have to remember that they have to fight into the target and back out again,
that means taking on all three fighter groups the further you go as well as 11 group again on the way back out, with every loss being not only a lost plane but pilot. I don't agree on the ammunition being overstated, eight .303 brownings in the spit and hurri are considered by many to be to light so two 8mm's in the 109 aren't going to win you many friends. Lastly as per the BoB, the Luftwaffe airman became increasingly dismayed at the RAF's ability to find and engage them from what appeared to be out of nowhere, and many times bad weather, bad timing or bad luck had fighters not meeting up with bombers or formations becoming scattered do to bad weather, like has been posted the outcome would be the same, a British win.
It has nothing to do with air currents and everything to do with trying to hit something flashing by you doing hundreds of miles an hour.
Park would continue his pealing away the fighters tactic so the deeper into England they go the more units they are engaging, you have to remember that they have to fight into the target and back out again,
that means taking on all three fighter groups the further you go as well as 11 group again on the way back out, with every loss being not only a lost plane but pilot. I don't agree on the ammunition being overstated, eight .303 brownings in the spit and hurri are considered by many to be to light so two 8mm's in the 109 aren't going to win you many friends. Lastly as per the BoB, the Luftwaffe airman became increasingly dismayed at the RAF's ability to find and engage them from what appeared to be out of nowhere, and many times bad weather, bad timing or bad luck had fighters not meeting up with bombers or formations becoming scattered do to bad weather, like has been posted the outcome would be the same, a British win.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
I suggest you take a ride in a Cessna 172 and once leveled off and cruising, open the windscreen and hold a broomstick out about three feet and try and hold it steady.
When you've mastered that, come back and let us know how that worked out.
I think the argument was the projectiles were disturbed by air currents, not the gun barrels?, by your example a bigger 20mm barrel would be harder to train than a thinner shorter .303/7.92mm so the gunners would be further disadvantaged using bigger guns.
I was too busy to read the entire convo, so my apologies if I missed something or the context of this post. But wind does affect the trajectory of a bullet, ANY bullet, and any size round, just as it does to any flying object. It is simple physics and aerodynamics. Some call it Wind Drift.
Wind has an affect on anything traveling in the air. Even aircraft. When navigating you have to correct for wind.
3.2 Effects of Winds - Sierra Bullets
http://www.physics.utah.edu/~mishch/wind_drift.pdf
https://www.rifleshootermag.com/editorial/ammunition_rs_bulletvwind_200906/84226
These articles are discussing rifle and pistol rounds fired at ground level where wind velocity is most likely much less than at the altitudes our aerial warriors are playing around in.
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RW Mk. III
Airman 1st Class
I don't think anyone was debating that point. More that the effects of wind on trajectory and other nuances are moot when precision-aim simply isn't happening/possible.
I think it could be conceded that an attacked making a direct and steady tail-on approach would give an opportunity for a marksman but pilots favouring this method probably wouldn't last long between tailgunners and escort fighters. But that's only my 2 cents.
I thought that the whole idea of a turret was to have the guns securely mounted and smoothly traversed. When you see footage of waist gunners in B-17s with the movement of the plane, gun and gunner plus the recoil, the effect is that he is just firing bullets in a general direction.
While I was never a fighter pilot, or bomber gunner, I think it does play a role in aiming. I do have 6 years of experience in aerial gunnery, including actual combat time doing so. Our gun sights were not precision gunsights either. We had to learn the way winds affect the tragectory none the less to determine how and when to aim. In our case we did not have to learn just the affects of the natural wind, but the wind created by the rotor wash. I would suspect prop wash would have an affect as well. I would also suspect that fighter pilots and bomber gunners would have to take these things into account when aiming at a moving aerial target regardless of its precision or not. A gunner/pilot has to take everything into account otherwise they are just shooting in the wind.
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Without the benefit of experience of any sort in aerial gunnery, I can say that with the little knowledge I do have of the subject that it wasn't simple to just plonk gun positions onto existing aircraft types, even when gun positions and turrets were designed into the aircraft, their impact on aerodynamics had consequences. The Manchester suffered severe vibration when that awful FN.7 mid upper turret was turned, turning the rear turret also caused buffeting. The Halifax suffered increased drag with the installation of the turrets designed for it, that had a detrimental impact on its overall performance.
Another issue that the British discovered with the installation of gun turrets on its pre-war bombers (the Blenheim, Wellington and Whitley) was that during exercises, gunnery accuracy actually decreased, as gunners did not receive sufficient gunnery training to adequately take advantage of the benefits the new power turrets offered. In 1939 the head of RAF Bomber Command, Edgar Ludlow-Hewitt, in a general rant about how poorly prepared his service was for a shooting war commented on the poor accuracy of the gunners in their new powered turrets and advocated a central gunnery training school to cater for the demands of the new technology. This was taken up.
I'm sure such things almost certainly would have affected the Germans in their new turrets as well.
Another issue that the British discovered with the installation of gun turrets on its pre-war bombers (the Blenheim, Wellington and Whitley) was that during exercises, gunnery accuracy actually decreased, as gunners did not receive sufficient gunnery training to adequately take advantage of the benefits the new power turrets offered. In 1939 the head of RAF Bomber Command, Edgar Ludlow-Hewitt, in a general rant about how poorly prepared his service was for a shooting war commented on the poor accuracy of the gunners in their new powered turrets and advocated a central gunnery training school to cater for the demands of the new technology. This was taken up.
I'm sure such things almost certainly would have affected the Germans in their new turrets as well.
RW Mk. III
Airman 1st Class
I'm curious about the optimal arc of fire for the 20mm's proposed to be defending the do19's or ju88's. Reading accounts generally indicates to me that one of the RAF favoured approaches was beam attacks on bombers. Given the speed of these two bombers that wouldn't exactly be difficult to position a spitfire or hurricane for even if they were overhauling the bombers.
What kind of coverage would the defensive guns have on a long sweeping turn culminating in a beam-on attack?
What kind of coverage would the defensive guns have on a long sweeping turn culminating in a beam-on attack?
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
Of course wind currents will have an effect on the trajectory of a bullet (or cannon shell) in flight.
On a bomber, the gun positions are not in "clean" air like the nose or wings of a fighter and then you have to factor in my commemt about the broomstick to understand that defensive weapons on a bomber are terribly inaccurate.
swampyankee
Chief Master Sergeant
- 4,306
- Jun 25, 2013
Was there any examination by the USAAF of how effective different gunner's stations were? I would suspect that the waist gunners were the least effective, but I've no data.
Initial argument is about the tail gun, so in some (or most?) cases the fighter will remain under the gunner's fire longer than the fractions of a second unless attacking from 6 o'clock high.
