Favorite concentrated armament package.

[Glider]

I have always been a fan of the Meteor with 4 x Hispano V 20mm in the nose.

 

[Shortround6]

Four 20mm Hispano MK IIs early in the war (Westland Whirlwind)

Four 20mm Hispano MK Vs when available.

A nice combination of shell weight, velocity and rate of fire.

 

[Condora]

Four 20mm Hispano MK IIs early in the war (Westland Whirlwind)

Four 20mm Hispano MK Vs when available.

A nice combination of shell weight, velocity and rate of fire.

@#£@#%!!!!!

I arrived to late to mention my beloved Whirlwind!!!

 

[DBII]

North American designed gun pods to be mounted on the B-25s for straffing. The first pod was attached in the hatch below the cockpit and contained two 50 cals. The second pod went into the bomb bay. I think it housed a couple of 50 cals and 2 cannons. These pods would be in addition to the nose guns and 4 in the gun packs. I have a photo and a drawing that I will try to post. The B-25 was also fitted with a flame thrower that was tested state side but never fielded.

DBII

 

[Colin1]

Fighter vs bomber: I would have to go with the 4 x MK108 battery offered by the Me262A. If it wasn't already done, I would have incorporated a facility whereby pilots could electically isolate weapons, with 2-3 rounds being sufficient to bring down a heavy, all 4 weapons firing at once seems to me to be a waste; being able to fire one gun at a time prolongs time on target and injury to the bombers.

Fighter vs fighter: 4 x 20mm would be ideal but I wouldn't complain with 6 x .50 cals.

 

[Thorlifter]

The P-61 had a good armament package.

4 × 20 mm Hispano M2 cannon 200 rpg
4 × .50 in M2 Browning machine guns 560 rpg

 

[Civettone]

Surprising no one mentioned Russian guns yet... Taken as a whole they were superior to their Allied and German counterparts.


Kris

 

[Condora]

Also surprising is that almost nobody gives much consideration to a full .50 configuration?

It was almost as good as a heavier gun, the plane could have more ammo (sometimes, guns too), and as far as I've heard, an armour good enough to stop it was never in wide use during the war.

Most of the airplanes using guns also had machine-guns, to compensate for the lower rate and ammo capacity of guns, and because early gun models also were unreliable. Then you have bullets with different trajectories...

None of these problems occur when you have an all .50 aircraft.

 

[Shortround6]

Also surprising is that almost nobody gives much consideration to a full .50 configuration?

It was almost as good as a heavier gun, the plane could have more ammo (sometimes, guns too), and as far as I've heard, an armour good enough to stop it was never in wide use during the war.

Most of the airplanes using guns also had machine-guns, to compensate for the lower rate and ammo capacity of guns, and because early gun models also were unreliable. Then you have bullets with different trajectories...

None of these problems occur when you have an all .50 aircraft.

The American .50 worked and worked rather well but it was far from "IDEAL".

It was rather heavy for it's actual power, something on the order of 1/2 the weight of the Hispano which was not a light gun. However some users rated the Hispano at being 3 times more effective than a .50.
See also some of the non-Hispano 20mm cannon. Some of which were lighrter than the .50 Browning.

See the links to Tony William's web site.

The ammo supply question is a good one.

How much is enough?

Some arcraft had capacities than went well past rediculous. One of my favorite examples being the Brewster Buffalo (OK, not a twin), some sources claim 800 rounds for EACH wing gun. ONE minute AND TWENTY seconds of firiring time. THis may be an error, 800 rounds in the wing (400 for each gun?) but if true you could have had 4 guns with 200rpg (20 seconds firing time) for the 2 gun/800rpg set up.

Edit> I wish the Whirlwiind hadn't been cancelled so early, A MK II version would have been very interesting but this might be a topic for another thread

 

[paradoxguy]

Four 20mm MG 151 cannon in ventral tray, 200 rpg
Two 30 mm MK 108 cannon in wing roots, 100-120 rpg

One 13mm MG 131 machine gun in flexible rear-firing installation if fighter carries two or more crew.

Engines: DB 605's 1475 - 1800 HP; DB 603 1750 - 1900 HP; BMW radials 1700 - 2100 HP; Junkers Jumo 213 variants 1776 - 1880 horsepower

I selected the gun combination for the general reliability and muzzle velocity and range of the 20mm cannon, with the 30mm cannon more than doubling the punch at closer range. The MK 108's were known to jam notably more frequently than other fighter guns, so this array is still lethal if the 30mm guns became inoperative. I chose the gun locations to minimize visual impairment from muzzle flashes, although this aspect is less critical in daylight use than nighttime.

I have no training in aeronautical engineering, so engines were chosen based on a combination of 1) the engine power of known examples of two-engined fighters (Ju 88G, Me 410, He 219) carrying roughly similar gun payloads 2) Known German engines powering both twin-engined and single-engined German fighters that flew operationally in WWII. Sufficient engine power will vary depending on total weight of aircraft, drag coefficients depending on overall design, and other desired performance parameters (speed, ceiling, climb rate, among others).

Trivia: although nowhere near the weight and bulk of my earlier fantastical proposed armament of four MK 103 cannon and four MG 151 cannon, some variants of the He 219A-7, I recall, carried four MK 108's and two MK 103's forward-firing, plus two more MK 108's in Schrage Musik installation. This configuration was probably negated by the fighter's performance; some references note the heavier He 219's had limited speed (360mph) and ceiling (26,000ft) and Eric Brown has noted the high wing loading that severely restricted its maneuverability.

 

[Condora]

Not only the ammo and weight:

Early guns had a lot of problems.

I'm not sure of the volumes involved in, but if the "swap ratio" can be used as a guideline, usually to put a gun on an airplane's wing, you loose 2 machine-guns (I'm classifying guns as >= 20mm and <= as machine-guns, I don't know if that is done everywhere).
And loosing a lot of ammo capacity at that!

That apparently doesn't happen with the .50, so you can still pack 8x.50 with about half a minute of ammo, instead of... a few seconds!
(I had checked one of the sites above, and it gives about 12s capacity for guns and 30s for machine guns)

You and I will have to trust my memory for this - I don't remember WERE I saw it compared -, but the trajectory of the machine-gun was "flatter" and longer than a gun's trajectory.

IMHO, having a "truer" trajectory, longer range, being able to shoot longer and throw more bullets in the same amount of time is very appealling.

 

[beaupower32]

Here is my plane!
Engines
Daimler-Benz DB 603A with 2 stage superchager and a 4 blade prop


Weapons
2 30mm Mk108 Cannons with 80 rounds per gun.
4 20mm MG 151/20 cannons with 250 RPG. 2 Guns would be in nose with 30mm cannons, and 2 would be in cheek pods like mounted on B-25. Also able to mount external 20mm weapon pods on wings and under fusalage. Will also be able to mount 2 bombs (of various size) one under each wing between engine and fusalage.


It will be a single place fighter with no defensive weapons. 60ft wingspan for better performance at high altitudes. Empty weight around 17,000 lbs with a max take off weight of 25,000 lbs. Max speed will be around 415mph with a range of 1,800 miles.


Now obvously im no aircraft designer and these are probably some unrealistic numbers. This is part of my imagination that is loosely related to the Me 410.

 

[Clay_Allison]

Surprising no one mentioned Russian guns yet... Taken as a whole they were superior to their Allied and German counterparts.


Kris

I don't know of any Russian Twin-Engine fighter. If they made their own Destroyer (РАЗРУШИТЕЛЬ?) aircraft with a pair of Mikulin or Klimov engines, it would certainly warrant consideration.

 

[Shortround6]

Not only the ammo and weight:

Early guns had a lot of problems.


IMHO, having a "truer" trajectory, longer range, being able to shoot longer and throw more bullets in the same amount of time is very appealling.

Depending on the "guns" and the year and the mounting.

Sticking with the Hispano here, it was designed to bolted to an engine block and did have a fair amount of trouble when mounted in wings. The early versions also used a 60 rd drum for a feed system. HIspanos mounted in fuselages with a heavier cradle/mounting apparently gave less trouble and belt feeds showed up on British aircraft fairly soon. Hispanos and .50 s actually had very similar rates of fire at times except that the Hispano didn't suffer from the barrel heating problems the .50 did.
This last may be a bit over stated. the Browing was good for about 75 rounds in one burst and then was suppose to have a cooling off period followed by bursts of only 25 rounds. However for an early war gun with 600rpm fire rate this measn an initial burst of 7.5seconds for a wing gun. Most peaple figured that 3 seconds was a good amount of time to keep an enemy aircraft in the gun sight.
Now do you want to have to go back and shoot the same plane several times or do you want to destroy it on the first firing pass?
The bit about "truer" trajectory needs a little thinking about too. most trajectory tables are at sea level or close to it. At 20,000ft the air is about half as dense and so has about half the drag on a bullet as at sea level. This means that differences in bullet shape/drag are going to have less practical effect at the higher altitudes. this is assuming the two projectiles start out at similar speeds.

 

[Clay_Allison]

IMO, the US should have converted the .50 BMG to 20mm in the same manner as the Japanese Ho-5. American H.S. cannon suffered from reliability issues throughout the war. An upgraded Browning would have given us a reliable 20mm cannon that would fit in the same mounts as our .50s.

 

[Condora]

Depending on the "guns" and the year and the mounting.
This last may be a bit over stated. the Browing was good for about 75 rounds in one burst and then was suppose to have a cooling off period followed by bursts of only 25 rounds. However for an early war gun with 600rpm fire rate this measn an initial burst of 7.5seconds for a wing gun. Most peaple figured that 3 seconds was a good amount of time to keep an enemy aircraft in the gun sight.

I'd say more like 1.25 seconds, which is a very short burst, but are those cooling off data at sea level?
Altitude plays some tricks on you: it's colder up there (and yet boiling point is lower...). If the data is at sea level (and stationary, out of the plane), probably the first burst could be streched a bit longer, to a more acceptable 2, 2-and-something seconds?

You wouldn't get much longer than that, unless the targeted guy is already dead. Otherwise, he'll get out of there any way he can, no matter how.

The bit about "truer" trajectory needs a little thinking about too. most trajectory tables are at sea level or close to it. At 20,000ft the air is about half as dense and so has about half the drag on a bullet as at sea level. This means that differences in bullet shape/drag are going to have less practical effect at the higher altitudes. this is assuming the two projectiles start out at similar speeds.

That works both ways: the smaller bullet also will be less affected by drag and shape, so it's trajectory will also change. In the end, gravity will take a higher toll on the bigger bullet, I think.

 

[Shortround6]

I'd say more like 1.25 seconds, which is a very short burst, but are those cooling off data at sea level?
Altitude plays some tricks on you: it's colder up there (and yet boiling point is lower...). If the data is at sea level (and stationary, out of the plane), probably the first burst could be streched a bit longer, to a more acceptable 2, 2-and-something seconds?.

I believe those are recommendations for aircraft guns. On the cooling note. while the air higher up is colder it is less dense and cooling ablility is dependant on both teperature of the air and the mass of the airflow. 1/2 the air density gets you 1/2 the cooling at the same temperature so it may tend to average out? Plus the 250-350-mph airflow is only going to help the aircraft gun vrs a ground gun. THey found that out in WW I

That works both ways: the smaller bullet also will be less affected by drag and shape, so it's trajectory will also change. In the end, gravity will take a higher toll on the bigger bullet, I think.

Actually smaller bullets usually have worse drag for the same shape. Gravity affects all projectiles the same. It is how far the projectile can travel in a given period of time that really shapes the trajectory.

 

[trackend]

Beaufighter not because it carried more but the dumpy nose and high cockpit gave really great vision so made it a real great ground attacker but if you add the rockets ect it was one mean death machine

 

[Condora]

On the cooling note. while the air higher up is colder it is less dense and cooling ablility is dependant on both teperature of the air and the mass of the airflow. 1/2 the air density gets you 1/2 the cooling at the same temperature so it may tend to average out?

Honestly, I don't know. But then freezing wouldn't be such a problem "up there"?

Plus the 250-350-mph airflow is only going to help the aircraft gun vrs a ground gun. THey found that out in WW I

Sorry, what? vrs? What do you mean, the airflow disturbing the trajectory?
I meant the airflow increasing the cooling of the gun.

Gravity affects all projectiles the same.

D@mn, I can't believe I wrote it that way (my apologies, Galileo)! What I meant is that the bigger bullet will be affected sooner, as I believe it's speed usually is lower to start with.

How come a smaller bullet has more drag? It doesn't have so much "frontal surface", so it should be better?

 

[Shortround6]

The increased airflow would help the cooling of the aircraft weapon.
THe freezing problem comes in when you fly anywhere from a 1/2 on hour to 4-5 hours before firing the guns.

Smaller bullets have less weight per unit of frontal area.
This is a generality of course but look at a few numbers.

8mm bullet has 50.24 sq. mm of frontal area and bullet weights of 9-11.5 grams
12.7mm bullet has 126 sq. mm. of frontal area and bullet weights of 33-48 grams.
20mm shells have frontal area of 314 sq mm and weight of 79-130 grams.

so going from the 8mm to to the 20mm you have about 6 times the frontal area but 7-11 times the weight.