Info on Me262 with the BIG gun in the nose

[KraziKanuK]

Another 262 oddball was the one with the glass nose for a bomb aimer.

 

[the lancaster kicks ass]

i don't think they were ever made were they?

 

[KraziKanuK]

i don't think they were ever made were they?

Well WNr 110555 made 6 flights in Feb 45 and another 10 in Mar, so would say it was built. On 30 Mar it was flown by a defecting pilot to Schock, near Magsburg, and captured by American forces.

Vol 2, pg289 in the 262 series by Classic even has an in flight pic.

There was also WNr 110484 which first flew on 22 Oct 44. In 22 flights it accumulated 8hr14min of flight time. On Jan 7 45 it went to E-stelle Rechlin.

 

[DerAdlerIstGelandet]

Hmm cool, I did no know any of those had actually been built.

 

[Lunatic]

Hitler had a fantasy of long range large caliber guns mounted on fighters destroying Allied bombers from outside defensive gun range. The Experten of course new this was foolishness. RoF was insufficient and recoil was extreme. Scoring hits from outside defensive gun range was next to impossible.

Consider, to use such a weapon you must sit behind the target, hold your position, and try to sniper them with the long range gun. BUT... the actual range (plane to plane) at 225 mph of the .50 to a target behind the bomber is well over 3000 feet!

In general, any extreme was ineffective. A good balance of RoF, velocity, and hitting power were needed for a gun gun to be truly effective.

 

[The Jug Rules!]

Wow Big gun...I never knew that model of me262 existed.

I wonder if the '262 would have been more successful if they had mixed armament, such as 2 20mm and 2 30mm cannon

 

[P38 Pilot]

Heh, Hitler and his dreams....

 

[KraziKanuK]

I wonder if the '262 would have been more successful if they had mixed armament, such as 2 20mm and 2 30mm cannon

There was a mockup of a 262's nose with 2 MK103s(72rds), 2 MK108s(65rds) and 2 MG151/20s(146rds). Quite the ballistic mix match.

One prototype was constructed that had 2 MK108s and 2 MG151/20s. The 20mm were the upper weapons.

The Me262/U5, WNr 112355, had 6 MK108s with 100, 85 and 65rds per pair.

Another proposal was to mount 4 MK312Cs.

 

[DerAdlerIstGelandet]

My understanding is that KG 200 used different mixes of armament in the 262 and the 4 20s was the best possible mix.

 

[MichaelHenley]

That is what I am wondering. I mean you mount a large cannon on most aircraft and shoot it, it is going to do something, whether that is slow it down or what not....

Indeed...
A friend of mine told me that he had heard of a beaufighter being fitted with two massive cannons (one on each wing, forgotten the type unfortunately) and the pilot swore that when they fired them, the plane was going backwards...
The plane couldn't get up to speed with the additional weight though, so that kind of reaction was almost inevitable.

 

[KraziKanuK]

KG200 Adler? Never came across any 262s assigned to this LW unit.

 

[DerAdlerIstGelandet]

Excuse me you are correct, I meant EK 262. I have been reading a book on KG 200 and it that is why that came to my mind.

 

[Haztoys]

I know this is old ..But theres alot of take about BIG guns in aircraft the last day or so...So I dug this up if anyone cares

 

[HoHun]

Hi Haztoys,

>I know this is old ..But theres alot of take about BIG guns in aircraft the last day or so...So I dug this up if anyone cares

Regarding the merit of big guns, a German committee on 16.2.1945 prepared a comparison study of the anti-bomber batteries considered by the Luftwaffe at the time.

Their analysis was based on the finding that an average of 0.36 kg of explosives were required to bring down a heavy bomber.

They calcuated the weight of the ammunition required to bring down a heavy bomber for each weapon considered, based on an even 5% hit rate for each weapon.

Then they used 6 barrels for the 15 mm weapons, 4 barrels for the 20 mm weapons, 2 barrels for the 30 mm weapons and 1 barrel for everything bigger, and calculated total battery weight and firing time required for one kill.

Finally, they ranked the batteries according to the product of total weight and firing time for a kill. (If a battery was twice as heavy as another, but required only half the firing time, they were ranked equal that way, so that was just a simple way of making the results comparable).

The resulting ranking (by reciprocal ranking value, best is 100%):

30 mm MG 213/30 - 100%
30 mm MK 108 - 72.8%
55 mm MK 412 - 48.5%
55 mm MK 112 - 47%
20 mm MG 213/20 - 27.2%
20 mm MG 151/20 - 26.2%
30 mm MK 103 - 23%
55 mm MK 214 - 12.4%
15 mm MG 151/15 - 5.6%
50 mm BK 50 - 5.2%

It's worth noting that the different muzzle velocities of the various weapon were deliberately ignored for this study since the findings of this committee were that high-velocity weapons had a higher dispersion than low-velocity weapons so that they offered no practical improvement of hit chances.

The EZ 42 gun sight that was capable of taking trajectory drop into account was (based on combat experience) seen as a better way to increase combat range than increased muzzle velocities or larger calibres. For the MG 151/20, good results had been achieved at 800 m combat range.

The study accepted that the intercepors would inevitably have to spend some time in the range of the bombers' defensive fire, as can be seen by the high priority for short firing times, which would reduce the exposure to defensive fire.

Regards,

Henning (HoHun)

 

[johnbr]

Great info.

 

[HoHun]

Hi again,

>Regarding the merit of big guns, a German committee on 16.2.1945 prepared a comparison study of the anti-bomber batteries considered by the Luftwaffe at the time.

I just found another study, published in Luftfahrt International 15, that compares the low-velocity MK 108 battery installed in the Me 262 with a high-velocity battery consisting of 2 x MK 103 and 2 x MG 151 (15 mm).

However, in contrast to earlier studies, the target considers weapons effect against Mosquito-sized jet bombers capable of a 750 km/h top speed, which the authors figured the Allies might field in the future.

MK 108 and MK 103 were assumed to fire mine shells, while the MG 151/15 was assumed to fire incendiary ammunition for the purpose of the study.

With standard reflector sight:

At 400 m range, the MK 108 battery is superior to the MK 103/MG 151 battery for load angles of up to 30°.

At 600 m range, the same applies as at 400 m range.

At 800 m range, the absolute hit chances drops so low that neither battery can expect a kill with the available ammunition supply.

With EZ 42 computing sight:

If an EZ 42 computing sight is used, muzzle velocity becomes a minor concern. Accordingly, the MK 108 battery becomes even more effective in relation to the MK 103/MG 151 battery.

Regards,

Henning (HoHun)

 

[Civettone]

Henning ... you're the man!



Kris

 

[Denniss]

Why should they have used the 15 mm MG 151 for testing ? AFAIR they used the standard MG 151/20 but it was just called MG 151.

 

[HoHun]

Hi Denniss,

>Why should they have used the 15 mm MG 151 for testing ? AFAIR they used the standard MG 151/20 but it was just called MG 151.

The report actually specifies "15 mm" throughout. I assume this was due to the desire for a very high muzzle velocity - the MG 151/20 did not reach the high figures of the MG 151/15 in that regard.

Regards,

Henning (HoHun)

 

[drgondog]

well it was one of those late war Luftwaffe experiments to make them still on the cutting edge till wars end over every other nationality.

It was a filure and was not going to be pressed further, the prescence of the successful R4M would be treated into mass production had 46 onward happened with a more controllable guided rocket system. Pulling jet mph off was not what the jet pilots wanted nor needed with the superiority in Allied fighters. From what I hae found the Mk 108's would have been pulled off in time and replaced by faster firing 2cm weapons with longer range and a slightly longer fuselage and streamlined canopy for speed and endurance

I always had the same feeling. Speculatively speaking a faster firing 20mm would have been a strong consideration. The 262s had a hard enough tome scoring with 30mm from close range with the closing speeds.

The 50mm (almost) reminds me of the 75mm gun in the modified B-25. It is only recently that the fire control systems work well placing a 105mm gun on target with the AC-130