Well, the Bf-109G had also the bulges and I dont think that the germans were no able to get the right MG 131.
It seems that the disintegrable links eyection chutes were internal on the Fw-190 and external in the Bf-109.
MG 131 in Bf-109G.
MG 131 in Fw-190A-7.
An answer to this has appeared:
“On those same last parts, two long bulges are present in addition to
the standard big bulges seen on the 109G-5/6/8/14 cowlings (I would
say this is a variant of the type 050 Bf109G cowling). On some
examples are also present two small bulges above those long ones,
these where covering MG131 recoil shock absorbers designed for FW190s
(which takes more place due to the FW190 larger cowling) the Avia
people had to use because of the lack of Bf109G MG131 recoil shock
absorbers later in the production, that why its seen on the plane…”
Tony Williams: Military gun and ammunition website and discussion forum
Back to the Mk 108.
Fw-190A-8/R2 , from left to right MG-151/20, BSK 16 guncamera, MK 108.
30x91mm RB ammunition:
Minengeschoss ausf A:
Basic HE ammo, 330 grams bullet carring no less than 85 grams of nitropenta explosive content, to make some comparative a standar stick grenade carry 115 grams of explosive. Impact nose fuse AZ 1587.
Minengeschoss ausf A m-Zerleger:
Like the earlier but with a self destruction device wich actuated after 3 seconds, green band on bullet.
3cm Brandgranate-patrone:
Filled with a incendiary bursting charge Ph Mg of 140 grams, 490 m/s initial speed
Minengeschoss Ausf C L-spur:
He-tracer improved, the ausf C ammo was a streamlined desing in order to achieve a more straight flying path. The ausf C carried a litle less explosive filling, about 72 grams. The base of the projectile allowed a traced element .The muzzle speed was 510 m/s.
Minengeschoss Ausf c glimmspur:
Same as avobe described, but a with a dimer, non smoke tracer for low light/ night shooting.
Minengeschoss Ausf c glimmspur M -zerleger:
Same as above but with self destruction. Very much used for the Night fighters in Reichs defense.
Free download,
Manual german proofing ground Rechlin 1943
Cartridges, color codes, projectiles, cases, primers, fuzes
factory drawings —
Nice, I put something of that in my Luftwaffe guns topic.
Thank you very much, Mr. Genkiedeskan. Indeed, it represents a very interesting publication. 
Bordkanone BK 3,7 , part I:
The bordkanone series in one comprised of land weapons adapted to aeronautical use.The luftwaffe favoured the 3,7 gun mostly for two purposes:
[ul]
[li]To engage bombers outside the range of their defensive machineguns
[/li][li]To destroy armor more efficiently than the MK 101/103.[/ul]
[/li]The BK 3,7 used the long recoil system to operate, a hidropneumatic damper cilinder was used to absorb the heavy recoil in the gun mounting.
It was feeded by one or two clips of 6 rounds. The ciclic rate was 140-150 rpm.
The gun had an overall length of 3750mm and it weights 295 kg.
Use in attack aircrafts:
The first aircraft to use the BK were some Ju-88 sin the variant JU-88P-2, this a/c had a couple of 37mm cannons in a large underbelly pod, the aircraft was front tested in late 1942 and probed to be effective agaist armor and artillery emplacements but too vulnerable to russian Flak.
Ju-88P-2.
The first really succesful use was achieved when it was installed on Stukas, in march 1943 an special detachment named “Panzerjagdkommando Weiss” tested in Crimea the first Stuka G-1. This variant was fabricated from JU-87D-5 with the wings MG 17s deleted and the large weapon used instead.
The strong wing of the Stuka designed to withstand the bomb load and the heavy G forces in high angles dived recuperations was very satisfactory when coupled with the BK shock absorber. The Panzerjagdkommando Weiss entered in action inmediatly over the russian bridgehead of Kuban destroying tanks and attacking ships. The famous stuka ace Rudel claimed as many as 70 landing boats destroyed with his new G-1.
Armorer with a 6 round clip, note that is a clip already inserted in the loading plate.
Gun armonization in a Ju-87G-2. Quite loud.
Guncam showing the effects of this weapon on russian landing ships:
http://www.youtube.com/watch?v=cU6OK1zSxKg&mode=related&search=
The BK 3,7 installations were later modified to take 8 or 12 rounds each.
BK 3,7 part II, in Hs-129:
The most proficient tank-killer of the luftwaffe was also equipped with this cannon. although in small number.
Some Hs-129B-2 wre converted to use an single BK in large ventral bay, this was feeded with a 12 shots clip. This variant ws called Hs-129B-2 /Wa (waffenträger= weapon carrier)
The counterrecoil cilinder was mounted below the gun, in the same way as the Luftwaffe field AA gun. Is idle to mention that despite the reduction in power compared with the Ju-87 this emplacement had the advantage of an easier gun armonization.
Factory shots, the last section of the barrel is not in place:
Just 25-35 of this variant were ever used.
And that is all for tonight boys, going to eat something 
Hello here are some close ups of the famous Waffenbehälter 81 Z.
The manual told us that one WB was firing forward fired by the pilot and one WB (mostly the right wing one) fired afterwards controlled by the reargunner.
Designed for the Ju 88 and Ju 57 the WB was used with a lot of other planes.
Thanks for that document GK.
Would this weapon, and its ammo be the one the British BESA gun, and ammo were based upon? This ammo was also not recommended for use in bolt rifles, but the Mod-98 would hold it fine. i have fired hundreds of rounds of it, with no ill effect on the rifle. but do not use it in the older 8mm rifles like the M-88, it’ll crack for sure. - Raspenau -
The Besa was based in a czech gun. Is the same cartrigde case but I dont know if that tank MG was capable to handle the high pressure verbersserte ammo.
The British-made 7.92x57 ball loading for the Besa fired a 198 grain bullet at 2,500 fps (12.83g at 762 m/s). The AP bullet weighed 178 grains and was fired at at 2,580 fps (11.5g at 786 m/s). These were to standard specifications, not the v-Munition.
Thanks for the quick reply, I wasnt sure if it was the same, but thought I would ask. -Raspenau -
You have all the experts togheter in here Tank G. :mrgreen:
Me-110G-2/R1 over München, ZG 76 February 1944, note the underbelly pod with BK 3,7.
I don´t think that this picture was taken over München :neutral:
I once visited the old Airport at Schleißheim once and it was the only Air Base for Me110’s around München and as far as i know the only 110’s which had seen action here had been these with the Lichtensteinradar and mostly Nachtjäger - i think this picture was taken near the front 
If you are interested vistit this page - the old halls and buildings are owned by the Deutsches Museum and you can also see a He111 (i read it was an Spanish CA something ^^) near some other nice planes (e.g. a Storch)
Nearby is also a veeerrryy nice Chateau (Schloss Schleißheim) and interresting to know is, that inside the garden was a huuuggee command bunker for the Airforce Units around Munich - especially used for the Abfangjäger Einsätze (it has a strange name - can´t remember) - after the war it was blown up and you can now only see the wonderful Barok-Styled Garden.
http://www.deutsches-museum.de/flugwerft/information
http://www.hotel-erb.de/flugwerft_schleissheim_muenchen.aspx?lang=en
Wow also in the Axis Factbook registered:
http://www.axishistory.com/index.php?id=112
That information was taken from “Zerstörer aces of WW2” by John Weal/Osprey publishing.
Perhaps that british author is wrong, or maybe those are from a base outside Munich but deployed over that city, note that some Messers had 2x300 liters droptanks to increase range.
