As usual Panzerknacker you have an awesome amount of information which always makes for an interesting and educational read.
Thanks V.W I have to complete that with information about the 13 mm ammo and the 20x80 mm cartrigdes for the Ikaria gun.
Munition of 13x64B for MG-131.
As I said before this was a reduced capacity case in comparative with other similar weapons.Very reliable however. It can manage bullets weight between 33 aand 38 grams and shoot them at more than 700 m/s. All the bullets use a metal driving band, the “B” in the designation indicates a Belt to adjust chamber headspace.
13 mm Panzergranatpatrone L’Spur
Solid steel armor piercing shot, with day tracer. Muzzle speed 710 m/s. Bullet weight 38,1 grams. The tracer endures about 1,5 secs enough for 700 meters flight. There was also a Phosphor filled variant wich improve the incendiary effect.
Armor penetration table for the 13 mm Panzergranate, the vertical columns indicates the plate thickness and the horizontal the angle (90 º being vertical ) The discontinued lines indicate the penetration with a 3 mm duraluminium plate at 20º, simulating an aircraft body.
Sprenggranate L’Spur
Explosive, tracer with head impact fuse. Even is dubious the real affectiveness of a HE bullet in this caliber it was widely used. Some variant even had a self destruction element despite it complicated fabrication. Bullet weight 34 grams, muzzle speed 750 m/s.
Brandgranatpatrone L’spur
Incendiary with tracer. Weight 33,5 grams, muzzle speed 755 m/s. The filling is a mix of barium nitrate and magnesium.
By the way, " advanced primer ignition " is not synonymous with “direct blowback”. API is what (allegedly) happens in an open bolt blowback weapon, i.e. the primer is supposed to be ignited before the breech block has come to a rest. an acquaintance of mine did some tests on this, his conclusion was that it doesn’t actually happen.
What did he test? Some sub-machine guns claim to have an element of API in their operation, but it can’t be significant because they use standard ammo which does not have a rebated rim.
The pre-WW2 20mm Oerlikon family, and the 30mm MK 108 and IJN Type 2, most definitely relied on API, however - they couldn’t have worked without it.
Tony Williams: Military gun and ammunition website and discussion forum
Well , when iIuse the API designation was obviously to the cannons, a .22 pistol work also with the blowback mechanism so…Aniway those are small details that did not bother my at all.
MG-FF in Fw-200.
He did his tests on a MAC-10.
Which explains it…as that uses standard pistol ammo.
I have seen calculations concerning Oerlikon-type API blowback cannon which show that if they were straight blowback, the breechblock would have to be ten times heavier. This would not only slow the rate of fire right down to a small fraction of the actual figure, it would mean that the gun would only work if kept level: if pointed upwards, the weight of the breechblock would be too much for the mainspring to push it back.
Tony Williams: Military gun and ammunition website and discussion forum
Tony, this is vaguely on topic since it concerns German aircraft guns, but I just had a look at the split breech page on your website – a different friend of mine has just been contracted to produce a couple of multibarrel weapons based on the World War I Fokker Motorgewehr, which was a multibarrel split breech design, for which Fokker had several German patents. I’m surprised you didn’t mention it, and I’m equally surprised that the principle was not taken further, since it is significantly simpler than the Gatling principle.
I’m sure that we will learn a lot about it once he’s made the prototypes.
That’s interesting - I have seen photos of a German multi-barrel engine-driven WW1 aircraft gun, but I didn’t know it had a split breech mechanism. Do you have any more details?
Tony Williams: Military gun and ammunition website and discussion forum
The Mauser MG-151 family Part 1:
As early as 1934 the Mauser technicians began the development of a new airborne weapon to replace and/or complemente the Oerlikons guns.
The MG 151 was designed in two different calibres at the same time, the heavy 15mm MG-151/15 and the MG-151/20 20 mm cannon. Interchangeability between both design was also provided.
MG 151/15.
The 15 mm heavy machinegun (incorrectly named cannon in some sources) was the first of the family to be introduced in service with the Me-109F2 in march 1941. The MG was operated by a short stroke recoil mechanism, both barrel and lock recoiled togheter and the the bolt is disingaged using a rotating bolts head.
Inner squematic.
The MG 151 used a large capacity bottlenecked case with gave a high velocity to the proyectiles around 850-960 m/s. That provided a straigth flying path to target and improve the chances of hit. Due the generous muzzle speed the Ap bullet could defeat any aeronautical armor in that time, including the mitic “ironclad” ilyushin Il-2 Sturmovik. The overall lenght of the gun was 1917 mm, width 190mm, weight 42,5 kg and it shoot at some 700 rpm.
MG 151/15 in Fw-200:
Loading a 125 rounds belt in a Hs-129B-1.
AIUI the MG 151 was first developed in 15x96 calibre, only later in 20x82; certainly the 15mm came out first.
As a matter of interest, the 15mm seems to have been more widely used than is generally thought. I have seen various pictures of what is clearly 15mm ammunition being loaded into planes which are supposed to have only been equipped with the 20mm version.
This pic from my website shows both rounds.
Tony Williams: Military gun and ammunition website and discussion forum
There is a good chance that both were designed at the same time , for example the first operative (maybe a prototipe) MG 151/20 was put in a Do-17e used by the legion Kondor in Spain in 1937, the aircraft did not have a long career being shoot down by the republican AAA near Asturias , none of the crew survived.
A friend of mine has a list of patent numbers relevant to this weapon. Next time I speak to him, I will ask him for them, if I can’t find them at home.
I would be very interested in knowing more about that report.
My information suggests that the 15mm version was designed and made first, for several reasons:
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The gun designation: at that time, the calibre formed the initial numbers of the designation, so you got MG 81 = 8mm, MG 131 = 13mm, MG 151 = 15mm, MG 204 = 20mm. The 20mm version of the MG 151 is designated MG 15/20, which looks like an afterthought.
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Every source I have states that the MG 151/20 design was adapted from the 15mm version in order to make use of the highly effective M-Geschoss shells developed for the MG-FFM. These did not enter service until 1940. The earliest production date for the MG 151/20 which I have seen mentioned is 1940.
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The 15mm gun entered service in before the 20mm.
The MG 151 - in any version - was nowhere near production ready in 1937 when it was reportedly found in a crash. Unless there is hard evidence (e.g. a photo of the gun in the wreck, with the ammo showing it to be 20x82) I strongly suspect a wrong identification. There were various Solothurn/Rheinmetall 20mm guns around at that time, and it was probably one of those.
Tony Williams: Military gun and ammunition website and discussion forum
The MG 151 - in any version - was nowhere near production ready in 1937 when it was reportedly found in a crash. Unless there is hard evidence (e.g. a photo of the gun in the wreck, with the ammo showing it to be 20x82)
Of course as I said it was probably a prototipe and yes there is evidence , the gun itself is in the Spanish Air force Museum. A report of this gun was in the ARMAS magazine Nº 138.
Do you think you could possibly tell me what the magazine said about the gun? (In English, preferably!).
Tony Williams: Military gun and ammunition website and discussion forum
I have not see references of this gun in english language publications.
Interesting pics of the triple mounting of Mg-151 /15 in He-280.
Between 1944 and 1945 a lot of surplus MG-151/15 were used as a drilling (triple) in the Sd.Kfz 251 half-track.
Actually I was wondering what the article in ARMAS magazine Nº 138 said.
Tony Williams: Military gun and ammunition website and discussion forum
Actually I was wondering what the article in ARMAS magazine Nº 138 said
Uuughh…what a man of little faith. I already told you. It was more or less the facts I ve descrived previously. I have that magazine. if you behave I going to scan something.