Figures given in the documents I have are:
2 cannons + 4 x .303 -- 663 lb
4 cannons -- 904 lb
This takes into account ammunition, feed mechanisms, mountings, etc.
UK goes all-in on a HMG class gun in the mid-30'ies
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Figures given in the documents I have are:
This takes into account ammunition, feed mechanisms, mountings, etc.
I dont really know anything about it apart from what you can get on line, and all pictures I have ever seen of 4 cannon Spitfires was at Malta. I thought it may have been to attack shipping, with zero evidence at all lol
The difference is 30 seconds to 20,000ft which is still better than just about everything else in the sky, but I feel your right, two cannons and four MG's are as good as it gets over Malta.
How much does 2 cannons and four .50 brownings weigh?, that was the prefered armament over four cannons alone.
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- #145
From the above quoted numbers we can solve for a single gun + ammo:
Hispano: 102.5 kg
.303: 24 kg
Elsewhere on the Interwebs we can find that the AN/M2 MG empty weight was 28 kg, and a single round clocks in at around 120g. So a gun + 250 rounds (which is what Spitfire .50 installations had) is 58 kg. In reality probably slightly more due to belt links and the trays for the belts etc.
Combine the above numbers in the combination of your choice.
That being said, I've never heard of the combination of 2 cannons + 4 .50 MG's on a Spitfire. AFAIK early installations were 2 cannons + 4 .303 MG's, with the 4 MG's later replaced by 2 .50 MG's. And then 4 cannons and no MG's in post-war installations in late Mk Spits. Maybe the 4 cannon installation was used for ground attack roles earlier or in special situations like discussed in this thread, IDK.
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- #147
Of course. But real life WWII aerial combat wasn't a video game where you can laser snipe someone at 1 km. It's not wise designing your fighter armament around statistically unlikely outcomes.
Shortround6
Major General
Well, they weren't "sniping".
152-160 rounds per second increases the chances of golden BBs over 50 or so projectiles a second even if they are bigger.
Things changed rather quickly in 1940. Jan 1940 had Spit Is with Merlin IIIs and a fair number (but certainly not all) planes being fitted the 2 pitch props.
July-Aug saw the Spit IIs start to show up with Merlin XII engines and the 2 Pitch props were history unless a few planes in OTUs still had them.
Dec 1940 saw the Spit V (still with eight .303s) just around the corner with Merlin 45 engines. With only about a 10lb change in engine weight power had gone up by around 20% (keeping the low boost ratings of the time) you could stick in heavier guns and ammo and still have a net performance gain.
The .303 was listed as 10KG while the .50 Browning was listed at 29kg. Trying to put one in place of two .303s is not that big a change although out near the wing tips was a bit of a challenge.
.50 cal ammo was the problem with many installations.
.303 ammo was just about 3 kg per hundred.
.50 cal ammo was 13.6kg per hundred. Much over 200rpg and the ammo weighs more than the gun.
20mm Hispano was about 28 kg per hundred rounds.
No sure if thats a typo? It wasn't - it was 2 x 20mm, 4 x 0.303. Only the XVI regularly flew with 2 x 20mm and 2 x .50 cals.
Clayton Magnet
Staff Sergeant
- 902
- Feb 16, 2013
2 x 20mm Hispano's, and 2 x .50 Cals was the standard "E" wing arrangement. And many Mk.IX and XIV used this armament in addition to the Mk.XVI.
If I remember correctly, it was the standard Spitfire armament with the introduction of the Ferranti Mk.II gyro gun sight, as the the 20mm and .50 had similar trajectories
Any idea when the E wing was introduced into operational service?
Clayton Magnet
Staff Sergeant
- 902
- Feb 16, 2013
From Wiki;
"The first trial installation (modification 1029) was made in BS118 in November 1943; by mid-March 1944 the first service Spitfires to be modified were from 485 (NZ), 222 and 349 Squadrons. Spitfires with this armament were at first referred to as Spifire LF.IX .5 and the E suffix was not officially introduced until early 1945. This armament was standard for all Spitfire Mk IXs and XVIs used by the 2nd Tactical Air Force as fighters and fighter-bombers from shortly after D-Day."
Glider
Captain
I made the difference to be 1.2 mins
They list 1055 lb (160 rounds/gun for 20mm, 210 rounds/gun for .5in).
They also say (Joseph Smith by the way) that "the possibility of incorporating this scheme is doubtful as a complete redesign of the aileron control system would be necessary". Emphasis in original. He also writes that the 20mm ammunition would be limited to 138 rounds/gun ... so in practice (if the redesign difficulty was overcome) I assume the weight would probably be a bit lower.
If you read the report from the previous page the recommendation was two cannons and four .50 BMG's over four cannons or two cannons and four .303's.
If you have access to Edger Brooks notes he states that the eight and later four .303 armament was used because they gave the best chance of incapacitating the pilot, it wasn't until gyro sights were developed that the E wing replaced all others.
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They were anyway, the control surfaces of the Spitfire were changed from fabric to metal, then they were reprofiled once combat speeds exceeded 400mph then finally the hinges were changed from single pivot to piano type.
A.G. Williams
Airman 1st Class
- 182
- Oct 10, 2020
I recall reading that the RAF studied ammo expenditure and concluded that 90 rounds per gun (Hispano) was adequate for the great majority of fighter missions.
