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By: - 1st November 2007 at 20:52 Permalink - Edited 1st January 1970 at 01:00
The RAF largely used .303 ammo in the turrets instead of .5 for the simple reason that, in the main, the turrets were fitted with .303 calibre machine guns. .5 ammunition wouldn't fit.
I believe .5's were fitted to some aircraft later in the war but I have no idea in what kind of numbers nor which specific types. I suspect that the fitment of .5's might have necessitated different turret design to accommodate the larger calibre weapon.
Regards,
kev35
By: - 1st November 2007 at 21:15 Permalink - Edited 1st January 1970 at 01:00
Wasn't it just the case that when the various specs were being written, .303 guns and ammunition were the most readily available? They did the job so why disrupt production by introducing different calibres?
Best wishes
Steve P
By: - 1st November 2007 at 21:16 Permalink - Edited 1st January 1970 at 01:00
30s for 50s
Not to mention having to change out the ammo boxes and tracking etc... shame really. Could you imagine the outcome with bomber command if they ahd heavier firepower in the turets!
By: - 1st November 2007 at 21:33 Permalink - Edited 1st January 1970 at 01:00
Not to mention having to change out the ammo boxes and tracking etc... shame really. Could you imagine the outcome with bomber command if they ahd heavier firepower in the turets!
thats my point thanks for stating it
regards vic:cool:
By: - 1st November 2007 at 21:35 Permalink - Edited 1st January 1970 at 01:00
Wasn't it just the case that when the various specs were being written, .303 guns and ammunition were the most readily available? They did the job so why disrupt production by introducing different calibres?Best wishes
Steve P
aclear case of using a cheaper substitute thereby placing the aircraft with less effective armament,and endangering its crews :cool: :
By: - 1st November 2007 at 21:59 Permalink - Edited 1st January 1970 at 01:00
Most British bombers flew at night, so perhaps an enemy fighter wouldn't have been seen at 50 cal range? Meaning for close range night fighting, .303 might have been a better option. A 4 gun turret could fire at upto 4600 rounds per minute, would this be better against a 'flash before your eyes' sighting of an attacking fighter?
By: - 1st November 2007 at 22:04 Permalink - Edited 1st January 1970 at 01:00
An upgrade to .5inch weapons would probably not have made a massive appreciable difference, the best place for a bombers defensive guns to be were in the wings/fuselage of its escort fighters!
Remember that the .5inch was the standard weapon for the USAAF bombers and without fighter escort they were decimated. Without Escort fighters the situation would only have got worse as the hitting power and range of the guns of German fighters progresivly increased.
By: - 2nd November 2007 at 02:48 Permalink - Edited 1st January 1970 at 01:00
Most British bombers flew at night, so perhaps an enemy fighter wouldn't have been seen at 50 cal range? Meaning for close range night fighting, .303 might have been a better option. A 4 gun turret could fire at upto 4600 rounds per minute, would this be better against a 'flash before your eyes' sighting of an attacking fighter?
All sorts of misconceptions in here ...
1. RAF Bombers flew at night because they got slaughtered in daylight - in part because of poor defensive armament, in part because unlike the USAAF the RAF didn't persevere and figure out formation tactics etc., and in part because the aircraft were vulnerable (little or no armour, etc.)
2. Taking learnings from how ineffective rifle calibre bullets were against armoured night fighters and the USAAF's experience; a two gun .50 cal turret was developed and fitted to some Lancasters later in the war - it packed serious punch and was loved by its crews
see FN-82 turret http://en.wikipedia.org/wiki/Nash_%26_Thomson
and a surviving Mark VII Lanc http://www.raafawa.org.au/wa/museum/lanc/history.htm
3. The whole issue of firepower was nevertheless of relative minor importance in the very short duration, predominantly unseen, combats with night-fighters. By far the majority of bombers lost never saw their attacker - read any number of accounts. This particularly so later in the war with the development of schrage musik
cheers D
By: - 2nd November 2007 at 07:03 Permalink - Edited 1st January 1970 at 01:00
All sorts of misconceptions in here ...1. RAF Bombers flew at night because they got slaughtered in daylight - in part because of poor defensive armament, in part because unlike the USAAF the RAF didn't persevere and figure out formation tactics etc., and in part because the aircraft were vulnerable (little or no armour, etc.)
Agreed. RAF realised quickly that daylight bombing wouldn't work the way they were doing it. Take those planes, and put them up at night, and things worked a bit better.. Interestingly enough, they were happy to persevere with the .303 at night when introducing newer bombers and variants.
The job of an air gunner on a night bomber was less defensive, but more oberservational. A keen eyed gunner, combined with the corkscrew maneuver supposedly saved many a bomber crew... All that said, I would have preferred being in an FN82 or Rose Rice turret with a pair of 50 cals with their greater punch, just in case!
By: - 2nd November 2007 at 08:21 Permalink - Edited 1st January 1970 at 01:00
I recently researched Lancaster and Bomber Command gunners for a feature in October's Aeroplane magazine. Mostly very sad and moving testimony.
Best reference is British Aircraft Armament Vol I. Gnome and Linrey are correct, IMHO, and the .50 cal wasn't a viable alternative for the British in the 1930s (when the turrets and aircraft were being developed). Even getting the Browning into British service was a tougher job than is realised, but the .303 round was also pretty inevitable given how much stock (I believe) was available from the Great War. The Rose turret was a big improvement, but in the thirties the thinking was to get the turrets to work properly, then to go to cannon - 20mm, jumping the .50 inch option, which really came into RAF use because of American arms production.
Boulton Paul were developing a cannon armed turret pre-war (Tested in an Overstrand) but it never went into service. Turrets are a bit touger than realised with larger calibre guns.
The gunners' main role was to spot the enemy fighter and direct evasion. Knocking them down was an extra. As Gnome says, with schrage musik, even the spotting the enemy became unlikely.
By: - 5th November 2007 at 09:40 Permalink - Edited 1st January 1970 at 01:00
why did the RAF mainly favour .303 ammo instead of .50 calibre for the gun turrets in bombers? as opposed to the USAF who used .50 calibre, was it a question of critical all up weight etc :cool:
I do not know the reasoning of using .303 brownings in gun turrets,but it never ceases to amaze me that 4 X .303's in concentration were acceptable for a heavy bomber when anything less than 8 was insufficient for a fighter,hence the specification for the early Hurricanes & Spitfires.
My only explanation is that the the strain of recoil from 4 or even 2 .50 brownings far exceeds that of 4 X .303's & was capable of over-stressing the early turrets.
For me the best British turret was the Rose design,it was designed for the .50,the wider seperation of the guns & reduction of rear facing glazing gave better vision (particularly when a shearch-light illuminated scratches & defects ) & allowed the gunner to evacuate by just rolling out & over the gunmount.Also from a comfort point,it was relatively draught free compared to the FN turrets(it was sealed at the back & the perspex was shaped so that the open face of the turret did not stray into the slipstream).Above all it could be fitted in the field to an existing aircraft without altering the airframe structure.
By: - 5th November 2007 at 10:30 Permalink - Edited 1st January 1970 at 01:00
I do not know the reasoning of using .303 brownings in gun turrets,...
The .50 wasn't available to Britain or the Commonwealth in the late thirties, but only when the US production became available during the war. As I said above, ammunition availability may be a factor as well; for various reasons Britain was wedded to the .303. We shouldn't look at if from what happened after but as regards what led to that. The intent was .303 interim, leading to cannon - the .50 was a late stop-gap.
Don't forget in the Munich crisis, equipment was rushed to bomber squadrons to fit Vickers K guns to plumbers drainipe mountings on bombers...
...but it never ceases to amaze me that 4 X .303's in concentration were acceptable for a heavy bomber when anything less than 8 was insufficient for a fighter...
A good question, in part answered by available technological limitations, but I suspect also that bombers were meant to be harder to knock down than fighters, hence the firepower difference. Also defensive armament is a secondary item - not the main warload of a bomber while a fighter's guns were its main weapon. Bear in mind there's no 'maximum best' but a question of performance compromise. More guns, less bombs. See the Escort B-17 failure as well.
As you observe, the Rose turret was superb. However, British turret design was remarkable, both in quick development and efficiency, and one of the areas where technology transferred to the US.
Regards,
By: - 5th November 2007 at 11:05 Permalink - Edited 1st January 1970 at 01:00
It has been touched on in some of the posts above - but commonality between the services would have been the initial motivator.
The Army used 303, so the WW1 RFC fighters used 303 and so it continued.
Pretty poor excuse though.
Moggy
By: - 5th November 2007 at 11:21 Permalink - Edited 1st January 1970 at 01:00
Thinking about what Radpoe has said above got me thinking about the different velocities of bullets fired from forward and rearward facing guns. Would a rearward firing .303 have more 'punch' than a forward facing one??
Just thinking out loud...
By: - 5th November 2007 at 12:25 Permalink - Edited 1st January 1970 at 01:00
The effect would be small - but the opposite way around.
The forward travelling bullet benefits from the addition of the forward speed of the aircraft to the acceleration from the propellant - the rearward firing gun needs its propellant to counteract the 200 - 300 mph velocity that the bullet already has in the opposite direction
Moggy
By: - 5th November 2007 at 12:31 Permalink - Edited 1st January 1970 at 01:00
Would a rearward firing .303 have more 'punch' than a forward facing one?
Correct…except that it would be the forward facing guns that would have more ‘punch’ (kinetic energy).
From a quick calculation would seem that the front guns of a Lancaster cruising at 210mph would have an extra 21% kinetic energy (against a stationary target) compared to a stationary gun.
A surprising difference! :)
By: - 5th November 2007 at 12:46 Permalink - Edited 1st January 1970 at 01:00
Thanks for the replies, but it doesn't quite cover what I was thinking. If you imagine a gunner firing rearwards into the front of an attacker, would that not cancel out the reduction in velocity caused by the speed of the gunner's aircraft? The effect as I'm imagining it would be like firing from a stationary gun into a stationary target, being as the attacker would have to be travelling at the same if not greater speed.
I'm down with a cold/flu at the moment, so my brain is pretty pickled at the minute and I'm probably talking twaddle (as usual :D).
By: - 5th November 2007 at 12:54 Permalink - Edited 1st January 1970 at 01:00
Yes, against an attacking fighter overtaking the bomber the rear guns would be more effective but only slightly so as the overtaking speed (difference) would be small.
Since we have been comparing the 303 / 50 calibres I did some more calculations…
…and it turns out that a single 50 calibre round has 585% the kinetic energy of a single 303 round (at the muzzle)! :eek:
Of course a four-gun 303 turret would fire a lot more rounds-per-second than a two-gun 50 turret. :confused:
Discuss.
By: - 5th November 2007 at 13:08 Permalink - Edited 1st January 1970 at 01:00
Yes, against an attacking fighter overtaking the bomber the rear guns would be more effective but only slightly so
And to extend it, the front guns would deliver a considerably heavier punch against a fighter going head-to-head.
Moggy
By: - 5th November 2007 at 16:57 Permalink - Edited 1st January 1970 at 01:00
I believe the Air Ministry issued a specification early in the war for a bomber with two twin Hispano 20mm cannon turrets, which I believe Boulton Paul had donw a lot of testing with. None of the suggested designs ever came anywhere near fruition, though Bristol built a mock-up, mainly because of the compromises the turrets created - they were so big and heavy that they had to be placed on the c/g meaning most of the bombs had to be carried in the wings.
What was interesting about this project was the the Air Ministry recognised both the inadaquecy of .303in ammunition, and the need for a clear and uninterupted field of fire above and below. One of the turrets was intended to be ventral, a notable ommission from most RAF heavies, to their cost.
Posts: 296
By: victor45 - 1st November 2007 at 20:36
why did the RAF mainly favour .303 ammo instead of .50 calibre for the gun turrets in bombers? as opposed to the USAF who used .50 calibre, was it a question of critical all up weight etc :cool: