What were the weight savings from removing FW 190 outer wing cannons?

[NickM]

Hi:

I have read that sometimes, some FW190 pilots had the outer wing cannons of their planes removed to save weight---especially with earlier marks of FW(A2 thru A5), where the outer cannon was the older MG/FF with a very different ballistic performance that the MG150/20 of later FW marks; So...how much weight did this actually save & how much of an improvement did it make in the performance of the FW? I imagine the reduction in firepower was moot, given that MG151s were much harder hitting & had a higher velocity & rate of fire;

Thanks, ahead of time;

NickM

[Leo Etgen]

Hi Nick

I remember reading a post on this discussion board by George Hopp in which the specifications of a Fw 190 A-4 with and without the outboard MG FF cannons were compared. If I recall correctly, the weight difference was 100 kilograms and the maximum speed without the guns was raised by 10 kph (no idea on what altitude this was at nor the effect on the climb rate). However, it would be nice to check with him or somebody else with available information before accepting this, as there were so many different variables involved (including my memory!).

Horrido!

Leo

[Franek Grabowski]

Weight does not influx horizontal speed, so if there was speed increase, it was due to better aerodynamics of the cannon-less wing rather than of any weight savings. Parameters that improve are climb rate and roll rate, quite likely the aircraft was also nicer to handle.

[John P Cooper]

Interesting question - here is sme additional information you may find helpful and may prompt someone to fully answer your question.


1) MG FF: Oerlikon Schweiz 20mm weighed 37 kg and fired 530 rds/min 100 rds weighed 33 kg (drum) or 21 kg (belt)

2) MG 151/20 Mauser 20mm weighed 42 kg and fired 630/720 rds/min 100 rds weighed 19.9 kg

So you could save about 150 kg for x2 MG FF if you remove the weapon and what ever bracket it was mounted with. (just a guess)

Cheers

John

[Tony Williams]

Originally Posted by John P Cooper

1) MG FF: Oerlikon Schweiz 20mm weighed 37 kg and fired 530 rds/min 100 rds weighed 33 kg (drum) or 21 kg (belt)

Ermm - the Ikaria-made MG-FFM weighed 26 KG and it never had belt feed (apart from an electric-powered device in some night fighters).

Tony Williams: Military gun and ammunition website and discussion forum

["bubi"]

Hi,

This operation which consists in reducing the weight of "jäger" in order to make it more powerful face to the enemy fighters was still in 1944 on more advanced marks like FW 190 A-8.

Sorry for my english

[Leo Etgen]

Hi guys

Interesting discussion. I am glad that others are responding to this question as I find it interesting as well. I would just like to point out that all sources that I have seen state that the Fw 190 series used a 55 round drum for the MG/FF, although I have also read about a 60 round drum that may have been used as well. On the post that I mentioned earlier I recall that the maximum speed was 646 km/h without and 636 km/h with the outboard guns. However, what configuration this aircraft, apparently a Fw 190 A-4, was in when tested, whether it was equipped with a bomb rack (s), the engine condition, other equipment fitted, etc. I do not know. I believe these were the results of a German test so it was not captured equipment. I would assume that the fairing over of the gun ports and deletion of the underwing bulges, like Franek points out, would contribute in no small measure to any increase in speed.

Horrido!

Leo

[John P Cooper]

Err the belt fed was experimental (due to mag capacity and jamming but I am not 100% sure maybe some experten can comment) sorry it was only added as a weight comparison...

[Tony Williams]

Originally Posted by Leo Etgen

I would just like to point out that all sources that I have seen state that the Fw 190 series used a 55 round drum for the MG/FF, although I have also read about a 60 round drum that may have been used as well.

It was always a 60-round drum, but may have been loaded with only 55 rounds to improve feed reliability. Some time in 1942 (IIRC), a 90-round drum with the same external dimensions was introduced.

Tony Williams: Military gun and ammunition website and discussion forum

[Tony Williams]

Originally Posted by John P Cooper

Err the belt fed was experimental (due to mag capacity and jamming but I am not 100% sure maybe some experten can comment) sorry it was only added as a weight comparison...

Yes, they made a rather Heath Robinson attempt at a belt feed, but I doubt that it was ever installed in an aircraft. The only people to produce a successful belt feed for the aircraft Oerlikon were the Japanese.

Tony Williams: Military gun and ammunition website and discussion forum