Interesting - I did not know about the 110E installation.
Tony Williams: Military gun and ammunition website and discussion forum
By the way Tony do you have any additional info about this Krieghoff experimental guns ?, because J.M Chinn in his book failed in provide the name of this.
The only one I know about is the 30mm MK 303, which was intended to arm the Type XXI Elektroboote. This was developed at the Czech Brno works under Krieghoff control. After the end of the war the Czechs carried on with the development and it eventually emerged as the M53 AA gun. It was normally seen in a twin mounting on the back of a 6x6 armoured truck. I saw one of these on television being used in the ground support role during the break-up of Yugoslavia in the 1990s. I gather that the remaining ones are now in reserve.
The 30x220 ammo is the biggest in that calibre to see service. See the pic below, from the Ammo Photo Gallery on my website. It is usually known as the 30x210 and I’ve called it that, but it’s incorrect (I must change the caption!):
Edit - sorry, brain fart: the capton is correct, I should have said that it is usually known as the 30x220 but the case does in fact measure 210mm.
Tony Williams: Military gun and ammunition website and discussion forum
Thanks for your help.
On request of Tony Williams.
Extracted from Revista Armas magazine Nº 138 november 1995.
In this first pages there is some pics of the aircraft ( the number 27-6 was the Mauser armed craft)
Pictures of the ammo salvaged from the crash, for those with trained eyes ( like the your and the mines :mrgreen: ) is more than obvius what ammo is…a 20x82mm with AP bullet and steel case.
And the rescued gun, with his serial numbers, the author requested more information from the mother house in Obendorf, the germans answered that all the records about the manufacture in that time were burned out by bombings in the war.
7,92mm and 13 mm effect over a Il-2, the pilots plate withstand both.
Uhumm…Tony ? is someone in there ?
Thanks very much - very interesting!
That brings forward the recorded date of the first use of the MG 151/20 by several years. I presume it was an early prototype - after all, it wasn’t until the experience of the SCW had been absorbed that the Luftwaffe abandoned the MG C30/L in favour of the MG-FF, as an interim weapon until the MG 151 was ready for service - which wasn’t until 1941, four years later!
Tony Williams: Military gun and ammunition website and discussion forum
Rheinmetall Maschinen Kanone MK-103
The good results obtained with the MK-101 and his cartrigde caused that the development of a improved weapon.
The new cannon would be more dedicated to the air-to-air combat, because the heavy weight and slow firing of the MK-101 made very inadecuate for that task.
Once again Rheinmetall Borsig put their hand on work and in the late 1942 they had his new design complete.[/FONT]
The MK 103 used a new system of short recoil with a bolt assisted by a gas to unlock the chamber, a hole in the barrel deviated a small quantity of the combustion gases and move a piston back.
That incremented the speed of the bolt s movement and therefore the rate of fire.
The MK-103 weights 145 kg, had an overall lenght of 2320 mm and his rate of fire was betwenn 380-420 rpm.
There was also a MK 103M variant, that was to be installed in the big V-12 engines like the Jumo 213 and Daimler DB-603. Is worth to note that despite some wrong sources the MK 103 was NEVER put in service with the Me-109K…simply because there was no enough room inside this fighter to put in, for that it would be needed to move the cockpit backwards about 20 cm, and still the gun barrel shall potrude through the Messers nose.
The MK-103M was almost the same as the standar gun, the only differences lay in the ausence of muzzle brake and some minor changes in the feeding system.
Not quite - if you look closely at the diagram you can see that the gas-operation tube of the MK 103M has been deleted - that part of the action had to be redesigned and slimmed-down to fit within the engine blast tube, as the gun had to be pushed further forward to clear the cockpit.
The MK 103M was tried in one Bf 109K-10 but the test was apparently not successful so it does not seem to have seen service. I’m not sure whether that was the model intended to be used by the Ta 152C and the Do 335, or whether a less-modified version of the MK 103 was planned.
Tony Williams: Military gun and ammunition website and discussion forum
Not quite - if you look closely at the diagram you can see that the gas-operation tube of the MK 103M has been deleted - that part of the action had to be redesigned and slimmed-down to fit within the engine blast tube, as the gun had to be pushed further forward to clear the cockpit
Damn, you are right, I wonder were the gasses go through ?
MK-103 in attack airplanes:
One of the first user of the new cannon was the Hs-129 from the Sch 1 in the Western front, The HS-129 armed in that way arrived to theirs bases in Ukrania in april 1943. This aircrafts had a stunning performance in the big armoured clash of Kursk.
3 images of the luftwaffe groundcrew feeding the Mk-103.
a)- Introducing the belt, note the mix between the Steel AP and Pzg
40.
b) Closing the receiver plate.
c) -In here the technical oficcer adjust the frontal support jack, this absorbed a big deal of vibration and thus increased the gun saccuracy.
MK 103 in Fw-190:
This gun was installed in two containers below the wings. Two types of containes were developed one for the FW-190A-5 and other for the FW-190F-8. 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-5/U11.
Teorically the electric ignition in this weapon allow to shoot through the propellers, however the test with an underbelly MK were a complete failure.
As far as I know, the MK 103-armed Fw 190s never saw action - the project was stopped at the test stage.
Tony Williams: Military gun and ammunition website and discussion forum
It probably was used in some Rechlin test.
MK 103 in fighters:
A Ju-88C night fighter with two MK 103 in a underbelly pod, note the angled barrels.
The 30 mm high velocity gun also was used in some special Me-262 like the Me-262A-1a/U1, it carry a heavy batterie, 2 x MK 108 plus 2 x Mg-151/20 and two more Mk 103 with 70 rounds per gun potruding through the nose. Just 4 or 5 A-1a/U1 were actually deployed, one was used by Heinz Bär.
The Ta-152C was one of the few single engine piston aircraft who could handle the MK 103 between the Jumo 213 V.
The Dornier Do-335 was another, in the B-2 variant also were one Mk-103 embeded in each wing.
I have never understood that armament installation - three different types of gun with three entirely different trajectories - it makes no sense at all.
The Me 262 standard armament of 4 x MK 108 was fine against bombers. If they wanted a higher-velocity armament for long-range fire, then 2 x MK 103 + 2 x 15mm MG 151 would have been a good ballistic match.
Tony Williams: Military gun and ammunition website and discussion forum
Perhaps they used the MK 103 for engaging bombers at long range and the other guns for close in combat, not really sure. Is know that Bär destroyed a P-47 with this special Me-262.
Me-262A-1a/U1 nose:
Rheinmetal Borsig MK 108:
In many ways, the Rheinmetall-Borsig MK 108 30mm cannon was considered to be a masterpiece of weapons engineering, due to it’s compact size, ease of manufacture and hitting power. Although it was first designed by Rheinmetall-Borsig in 1940 as a private venture, the design was finalized in 1942. It met a later RLM requirement for a new aircraft cannon that could knock down enemy bombers with the lowest expenditure of ammunition.
In the service position.
In short, the MK 108 was a blow-back operated, rear-seared, belt fed 30 mm cannon using electric ignition and was charged and triggered by simple compressed air. One drawback was that once installed, there was no method to adjust the gun's harmonization. One distinctive physical feature was the very short gun barrel, which gave the MK 108 a low muzzle velocity of 500-510 meters per second. The maximum rate of fire was 650 rounds per minute. The operating sequence for the MK 108 went like this:
[ul]
[li]An ammunition can fed the rounds to the gun by means of a disintegrating belt
[/li][li]Once the sear was released, the bolt went forward under the action of the two driving springs
[/li][li]A projection on the top of the bolt passed through the ring, thus extracting a round
[/li][li]This then forced the round into the chamber and fired the round while the heavy bolt was still moving forwards
[/li][li]The empty cartridge case reinserted itself in its link after firing
[/li][li]Ejection was achieved by means of pawls activated by camming grooves that were cut into the top of the bolt
[/li][li]Finally, the new round slipped into position and the sequence repeated[/ul]
[/li]With adaptator to DB-605 engine (BF-109G)
An interesting feature was that neither the barrel or receiver moved in recoil, the entire force of firing was absorbed by the rearward movement of the bolt against the driving springs, which buffered against the recoil. No locking mechanism was needed, because by the time the fired round had overcome the inertia of the firing bolt, the round had left the barrel and the pressure had dropped.
The nose mounting in a BF-110G.
There were two main types of ammunition for the MK 108 to use, a 30 mm high-explosive self-destroying tracer ("M-Shell" or "Mine-Shell") and a 30 mm incendiary shell. The first type was designed to cause a maximum blast effect by combining a very thin shell casing with the maximum load of explosive. Tests carried out at Rechlin (where most of the Luftwaffe aircraft and weapons tests were done) showed that with a "M-Shell" with 85 grains of explosive, five hits could destroy a B-17 or B-24 bomber. The second type of shell, the incendiary, was meant to be targeted at the fuel tanks of the enemy plane. Since some penetrating force was still needed to overcome the armor or airframe of the target, and not have the shell break up or explode upon contact, a hydrodynamic fuse was fitted so that the shell only exploded once it came into contact with liquid.
Text by. www.luft46.com
Pics and corrections: By me.
I have a question about the MG 131.
After the war, the Bf 109 continued to be made by the Czechoslovaks as the Avia S-199. The big bulge in the cowling (to make room for the MG 131 gun breeches) sometimes had additions in the form of a long, forward-pointing extension. This was reportedly because they could not get the correct version of the MG 131, so had to use ones intended for the Fw 190 which did not fit so well.
I find this puzzling. The only explanation which comes to mind is that the guns in the Fw 190 might have been made with the ammunition feed on the opposite side? Can you shed any light on this?
Tony Williams: Military gun and ammunition website and discussion forum