Luftwaffe Cannons and Machineguns topic.

[CharlesBronson]

Quote to self, page 6:

MK 103 in FW 190:

This gun was installed in two containers below the wings. Two types of containers ( Waffenbehalter) were developed, one for the FW-190A-5 and other for the Fw-190A-8 and F-8. In both cases the gun in this emplacement was feed by a metallic belts of 32 cartrigdes. It seems that the recoil forces and vibration were too much to the Focke Wulf ( despite the strong fabrication of the Wurger wings) and just few aircraft were armed in this way.

FW-190A-8/R3 .

Teorically the electric ignition in this weapon allow to shoot through the propellers, however test with an underbelly MK was a complete failure since the variation in rate of fire caused some "hang" shots, with the predictable consecuences.

Aparently the hang shots were not caused by a mechanical unreability of the MK but for the large grain of its propellant.

How about a target/reflector in the breech end. The device on the muzzle end has cross hairs and you look thru the barrel at the target in the breech end. If perfectly centered in the muzzle device's cross hairs, you can verify straightess of the barrel.

Pure conjecture on my part.....

It could be, I need to search more information about that apparatus.

 

[razor1uk]

About the optical viewing device, there was probably someone in the 'pit' with a torch/light shinging into the open breech (the cannons reciever body was located between the pilots legs ahead of the flight stick.
As for the cross hairs and such, persons with heavy weapons inspection knowledge might be able to advise; I suspect the thoughts posted are close to the truth.

I have a book by Uwe Fest, the 'Me 109' and for that pic, it (if my memory is working) 'Checking the Engine mounted MG15/20 cannon with a borescope on a unsuaslly painted Bf109F-... somewhere on the Eastern Front(I forget the subtype number).'

 

[tomo pauk]

Let me add/clarify the issue about 'aligning the barrell'.
It was the sight that was actually aligned against the gun barrel and not vice-versa, since it was hardly possible to adjust alignment for a motor cannon.

 

[Crimea_River]

Yeah. I wasn't talking about boresighting. I was talking about checking whether the barrel itself was true and straight.

 

[Civettone]

Let me add/clarify the issue about 'aligning the barrell'.
It was the sight that was actually aligned against the gun barrel and not vice-versa, since it was hardly possible to adjust alignment for a motor cannon.

Tomo, you never cease to amaze me!


Kris

 

[Erich]

a note but the oversized MK 103 external package on the Fw 190A was not used operationally but only as a test bed. we have discussed this on the site numerous times as to why it was not used. the same applied for the external short barreled Mk 108 in a waffen pod container

 

[Civettone]

Erich, can you please tell me some more about this. I read the reason for dismissing those MK 103s was because it "twisted" the wings, I suppose because of the heavy recoil. This would not have been the case for the MK 108s. Right?

And do you know anything about tests being done by external cannons under the belly and sychronized with the prop?

I was once thinking of a Hs 123 with a MK 101/103 strapped underneath its belly... That is the main reason why I am enquiring about this.

Kris

 

[CharlesBronson]

RZ 65:

1943 experimental air-to-air spin stabilized rocket, tested in special underwing pods on BF-109F.

 

[Alpha]

Hi all

Been a "lurker" for a while here and enjoyed the pics and information from the menbers.

I have a question regarding the BK3.7 rate of fire fitted to Stuka G1 Bf110 G2

Where the sources I find range from between 80 - 160 rpm does anyone know what the correct rof is ?

Thanks in advance and sorry I have a question as my first post.

Regards

 

[Shortround6]

Hi all

Been a "lurker" for a while here and enjoyed the pics and information from the menbers.

I have a question regarding the BK3.7 rate of fire fitted to Stuka G1 Bf110 G2

Where the sources I find range from between 80 - 160 rpm does anyone know what the correct rof is ?

Thanks in advance and sorry I have a question as my first post.

Regards

The variation may come from the difference between the cycle rate of the gun ( how fast the action cycles) and the practical rate of fire. The pauses while fresh ammo is feed into the gun. At least this is what the difference was for the AA guns.

In the case of the JU 87G what ammo was available was in the the feed way but perhaps the guns were fired in single shot to keep from throwing the aim off too much?

Did the 110 installation have a continuous feed or did the rear gunner change magazines or insert clips into the feed ways like he did for the 20mm MG/ff guns?

 

[CharlesBronson]

Dear Alpha:
The most usual rate of fire for the BK 3,7 was one between 130 to 150 rpm. I never heard or read of such low figures of 80rpm ciclical.

Did the 110 installation have a continuous feed or did the rear gunner change magazines or insert clips into the feed ways like he did for the 20mm MG/ff guns?

The Me-110G2 37mm gun was feed with 6 round clips by the rear gunner, more info and squematics in page 7 and 8 of this topic.

 

[Alpha]

Hi

Thanks for the information, could you furnish me with the source of your data so I can have a look, I'm trying to present accurate sourced rof for the Bk37.

Any hard copy reference material to hand will be useful, I tend to steer clear of things like Wikipedia etc etc.

I'm at Duxford Monday resourcing some other documents there, will see if there's any reference info for Bk 37 if I'm lucky

 

[Alpha]

Well no luck at my Duxford trip !!!

Seems elusive this Bk37 data

 

[Shortround6]

Well no luck at my Duxford trip !!!

Seems elusive this Bk37 data

Tony Williams book/s say 160rpm cyclic. Problem is rear gunner trying to jam a fresh 6 round clip in the gun every 2.66 seconds.

 

[Alpha]

I can see the choice of being able to dump a whole clip in under 3 seconds or single shot " plinking" would be an advantage depending on the situation.

I wonder what source TW used for his book ?

I'll make enquiries at Das BundesArchive see if they can dig something up also

Cheers

PS: As a side note ... did the Stuka G1 use a 6 round clip in each Bk37. this would give the pilot 6 shots with 12 rounds, a very limited loadout.

 

[CharlesBronson]

Actually it used 12 rounds with 2 clips in each gun, if you go back to page 7 you ll see photos of it.

 

[Alpha]

Many thanks

 

[brewerjerry]

Hi
From the excellent cockpit instruments a parts list for a 20mm MG FF
cheers
Jerry

 

[Ernst]

Bullet markings for the high pressure V ammo:

The armor piercing round penetrate 10 mm steel plate at 100 meters in a 90 degrees angle.

By the marking schemes and picture I would guess they used more than one type of ammunition in the same belt, firing API bullets together with normal ones. Is this true? What is the most common configuration of ammunitions?

 

[CharlesBronson]

Not quite, you need to take in consideration that the lower photo has been taken by a collector not a luftwaffe armourer so is not 100 % correct. So far the use of rifle calibre "ball" or normal ammo I know in ww2 is in the british side and just in the early years 1939-41.
The germans usually emsembles their belts for fighters with an combination of armor piercing, armor piercing incendiary, armor piercing tracers, tracers and observation ammo, the later known as B-patrone could be considered as an small SAPHEI since it had an small steel core for detonating the pentrinte charge.

In the Luftwaffe bombers the use of the very smoky "leutchspur" day tracer round was higher to enhance the "deterrent" effect.