6 PDR Mollins aircraft cannon ammunition

[=FB=VikS]

By photos of the canon and judjung by its auto-loader construction - it only can carry AP shots - as HE shell are longer than AP and wont fit into loader

 

 

but some  sources states that it had HE shell? Is that a mistake or smh?

Anyone?

 

 

 

 

[ZachariasX]

If I read this:

 

BRITISH 6 pdr AMMUNITION

 

From left to right: the 6 pdr 8 cwt (57 x 307R - naval plus WW1 tanks); 6 pdr 10 cwt (57 x 464R - coast defence "Twin Six" plus some ships); four 6 pdr 7 cwt (57 x 441R) loadings - AP shot, APCBC shot, APDS (repP), HE (postwar - WW2 HE shells were similar to those shown with the 6 pdr 10 cwt, in two different lengths); 6 pdr 6 cwt (57 x 515R - experimental AA gun cancelled in 1946).

 

(From here: https://www.quarryhs.co.uk/Molins.htm)

 

correctly, then the actual HE shell is actually shorter as that bullet would be on the same shell casing as the AP (57x441R) and not on the slim one (57x464R). You can see that on the postwar HE round. If they ever were to use HE experimantally, then it had to be a shell in the "post war" layout. But as the naming suggests, had that been common practise, then the suitable HE shell would not be referenced as "post war".

 

Also, in this reference, for the Tsetse gun they say:

 

[...] The gun normally used the plain AP shot [...]

 

that both sais that in principle it could be loaded with other types of ammo, but operationally this was hardly done. Which makes sense.

 

I think it would be a very silly idea to use HE ammo against naval targets, especially U-Boats. Any bullet that was to strike something below (where you should aim for) the water line, it would be set off the fuze once it hits the surface. If I had only a couple of shots that I could take I'd certainly reffrain from taking HE. But mechanically, I'd see no reason why a HE on the suitable shell casing wouldn't work.

[Denum]

Time stamped with a pilot of 248 Special Detachment, his recollection is that they only shot APT.  

[LukeFF]

Nothing in the Operations Record Books for 248 and 254 Squadrons points to what sort of ammo was used, but if they only used AP RP-3 rockets on Coastal Command Mosquitos, then they probably also only used AP shells with the 57 mm cannon.

10 hours ago, ZachariasX said:

(From here: https://www.quarryhs.co.uk/Molins.htm)

 

That link also says: "The gun normally used the plain AP shot (that is the only one shown in photographs), so had a high muzzle velocity of 890 m/sec (2,920 fps)."

 

So, it sounds like AP-only to me.

[Denum]

1 hour ago, LukeFF said:

So, it sounds like AP-only to me.

 

 

I'm curious if we will be able to use it like they did during shipping strikes.

 

They shot at the water slightly before the target and used the water to help deflect it into the side of the ships below the waterline. 

 

 

 

Part of me says it needs HE as you can't destroy some of the static tanks using AP. 

 

From a gameplay perspective HE would be nice. But I suspect there will be plenty of fun targets in the channel for it.

 

 

[LukeFF]

10 minutes ago, Denum said:

Part of me says it needs HE as you can't destroy some of the static tanks using AP. 

 

These planes were never used for antitank missions. 

[Denum]

8 hours ago, LukeFF said:

 

These planes were never used for antitank missions. 

 

8 hours ago, Denum said:

From a gameplay perspective HE would be nice. But I suspect there will be plenty of fun targets in the channel for it.

 

Yes I'm aware. Her deployment scope was extremely narrow and didn't last to terribly long either. 
 

[[F.Circus]Gorn_Captain]

I've been reading 'Most Secret Squadron' by Des Curtis, a navigator who crewed Mossies with mollins guns. In a description he gives of the gun he explicitly mentions it firing 'Armour Plated HE shells. Presumably he means Armour Piercing HE? But regardless later on while actually describing actual attacks, he mentions a lack of HE. 

Quote

 

This variant of the Mosquito was quickly christened the Tsetse from the African insect similar to and just as harmful as the Mosquito. The arc-shaped magazine, holding 24 rounds of 57 mm armour plated HE shells capped with Tracer, was positioned vertically about midship, feeding into the breech block.

 

 

Quote

 

Each Mosquito fired most of its 24 rounds. As the shells were armour piercing, without HE, no explosions were seen; the intention being to riddle the hull with 12 inch diameter holes. The photographs taken by the navigators showed that many direct hits were obtained.

 

Curtis, Des. Most Secret Squadron: The First Full Story of 618 Squadron and its Special Detachment Anti-U-Boat Mosquitos . Grub Street Publishing. Kindle Edition. 

 

 

The former is possibly a poor recollection (which seems a little unlikely to me, given the amount of research and conscious attempt to avoid anything autobiographical in the rest of the book). It seems to me that it was possible for the Mollins to load HE, but it was never operationally used because as others have pointed out, it simply wasn't useful against their intended targets. 

 

[PivoYvo]

Another thing that´s maybe interesting for this gun ist the fact that, The cyclic rate of fire was just under one round per second. As no problems with blast or recoil had been discovered, on June 9 HJ732 was flown to Boscombe Down for air firing trials, where it was found that the feed unit would not work above 2.5g, a problem that had been predicted by the RAF Gun Section. The charger arm and other parts were strengthened and an automatic muzzle cap fitted to prevent the problem of ‘blow-through’ when the breech was opened. This was an important part of the design – as without it a 300mph (~485km/h) gale would have blasted down the barrel – yet it needed to be fail-safe and was designed so that – if it did not open – a shell could safely pass through it. The uprated charger arm cured the g-related issues, and (as long as sideslip was avoided while firing, which could cause a jam) the M-Gun was quite reliable.

 

 The space which would have been occupied by the 4 x 20mm British Hispano cannon was now filled with the Molins-modified 6-pounder and its auto feed system containing X rounds of HE ammunition with an armour-piercing nose; the big gun was offset from the centreline of the Mosquito by 4º, to accommodate the stock of large shells.

 

Hope this Helps a bit.

Edited December 10, 2021 by PivoYvo

[LukeFF]

On 11/4/2021 at 2:19 PM, [F.Circus]Gorn_Captain said:

I've been reading 'Most Secret Squadron' by Des Curtis, a navigator who crewed Mossies with mollins guns. In a description he gives of the gun he explicitly mentions it firing 'Armour Plated HE shells. Presumably he means Armour Piercing HE? But regardless later on while actually describing actual attacks, he mentions a lack of HE. 

 

The former is possibly a poor recollection (which seems a little unlikely to me, given the amount of research and conscious attempt to avoid anything autobiographical in the rest of the book). It seems to me that it was possible for the Mollins to load HE, but it was never operationally used because as others have pointed out, it simply wasn't useful against their intended targets. 

 

Des Curtis was recently interviewed by James Holland on the We Have Ways podcast, and he mentions using "solid shell" rounds when making their attacks. The interview link is here: 

 

The Mosquito Story - Part 2. Episode: https://shows.acast.com/wehaveways/episodes/the-mosquito-story-part-2 . Media: https://sphinx.acast.com/p/acast/s/wehaveways/e/622f6cb795b8930012a4860b/media.mp3 . -- Sent from Podcast Republic. 

[Sternjaeger]

the Tse Tse was specifically intended for anti-shipping/antisub missions, therefore what they really needed was a projectile that could poke holes in ships' hulls, this is the same rationale for the use of RP-3 rockets with the 25lb ballistic AP heads. Perhaps the note of interest there is that there were two variants of the AP heads, which were intended to be fired at different angles into the water before the target. There's quite some extensive original material on that if it's needed. 

Edited October 13, 2022 by Sternjaeger

[Peachy9]

In the UK National Archives last week and found an interesting Commitee file note document from ACM Portal re the Tse Tse. In it he makes a clear case that after the prototype Tse Tse had been tested they had decided that development of the Rocket Projectile for Mosquitoes was a better way forward. Next to this document was a letter from De Havilland stating that they already had 3 Tse Tse nearly complete and 27 more on the production run and that it would be disadvantageous for the Mosquito production process to stop production at that stage. So ACM Portal approved the full run of 30 in order not to disrupt De Havilland in any way. I believe that of these 30, 13 were converted back to FB IVs. Simple as that - almost scrapped before it came off the drawing board and not widely used outside of one or two flights.

 

Personally would have preferred in game for the Mosquito to include the Bomber MkIV Variant as it was widely used alongside the Boston for 1942 and first half of 1943 in low and medium level bombing by at least 3 squadrons.

[busdriver]

7 hours ago, Peachy9 said:

So ACM Portal approved the full run of 30 in order not to disrupt De Havilland in any way. I believe that of these 30, 13 were converted back to FB IVs [VI]. Simple as that - almost scrapped before it came off the drawing board and not widely used outside of one or two flights.

 

If you look through the Mosquito AM Form 78s for the 17 Mk XVIII, their deliveries were spread out amongst the Mk VI serials. Not to post each of the Form 78s, but on page 92 of Sharp & Bowyer's Mosquito (and if you squint ?) you will see the deliveries were very slow and drawn out.

Jun 43: 1

Sep 43: 1

Oct 43: 2

Feb 44: 1

Apr 44: 1

Jun 44: 2

Jul 44: 2

Aug 44: 2

Sep 44: 1

Oct 44: 1

Nov 44: 1

Dec 44: 1

Jan 45: 1

I've found no reference of production XVIIIs being converted to VIs during the war. Meaning I think Portal or another authority revised the order, limiting it to the known 17 production airframes and only 13 of those saw operational service. And this decision was before 143 Sqn flew the first Op of Mosquitos equipped with RPs in Jan 45. Reading the ORBs, I think at one point 248 Sqn flew one mission (21 Nov 44) with 6 x Mk XVIII, otherwise it was typically one or two (and a couple of times with four). 

 

 

7 hours ago, Peachy9 said:

Personally would have preferred in game for the Mosquito to include the Bomber MkIV Variant as it was widely used alongside the Boston for 1942 and first half of 1943 in low and medium level bombing by at least 3 squadrons.

 

I would also like a Mk IV variant in the game, for historical day low level ops.

 

Minor point of order, only two squadrons (105 Sqn and 139 Sqn) flew bombers with 2 Group prior to joining the Path Finder Force (or Pathfinder Force depending on your reference source) in Jun 43. 109 Sqn would pioneer Oboe operations beginning Dec 42, but that was a different mission. 192 Sqn formed in Jan 43 by re-designating 1474 Flt  (who acquired 4 x Mk IV in Nov 42) flew their first night RCM Op with their Mosquitos in Jun 43. 

 

 

 

PS: I envy your access to TNA.

[Peachy9]

Interesting - thanks for that. Yes I was including 109 with its Oboe Mossies in the 3. From the Docs I was reading there seemed to be quite a lot of meddling by the AM (they had a Mosquito committee - minutes of which I was browsing) and converting of Mosquitoes on the production line from one variant to the other seem to happen. It was suggested that the other 13 were in fact not completed as Mk XVIII but completed as FB MKVI as required. In some cases with additional fittings for MkXVIII remaining in situ in some cases. It was clear from the notes that demand from all branches for Mossies outstripped supply.

[busdriver]

@Peachy9 have you read anything specific about FB VIs (some PZ and NT serials) that wound up with AI installed? I know the Serrate squadrons (141 Sqn, 169 Sqn, 239 Sqn and later 515 Sqn) received some FB VIs equipped with ASH & Serrate upgrades.

[Peachy9]

There are whole files on the employment of the Mosquito in night fighting and the use of AI/Serrate and Monica. I can take a look next time I am there - I haven't even skimmed the surface!

 

I was there researching 105 and 139 so focus was on them and on the Bomber variant and stumbled over the letters re Tse Tse. What was also interesting was a very contradictory analysis of the Mosquito bomber. In April 1943 (which was clearly actioned) there was strong argument that it was ineffective as a bomber and had a high loss rate of 10% as a medium bomber - this argument won through and 105 were converted to Obe and 139 earmarked for Highball.

 

A year later the argument was that it was far more efficient (in terms of bombs dropped per aircrew lost) as a bomber than the main force and more FBs and PRU frames should be converted to the 4000lb bomber variant (their words).

 

I guess it shows how much Main Force casualties went up from June 1943 to June 1944!!

 

[Peachy9]

Quote

Posted November 13, 2022

@Peachy9 have you read anything specific about FB VIs (some PZ and NT serials) that wound up with AI installed? I know the Serrate squadrons (141 Sqn, 169 Sqn, 239 Sqn and later 515 Sqn) received some FB VIs equipped with ASH & Serrate upgrades

 

 

• Inllation of A.I. in Mosquito aircraft

  Ministry of Aviation, predecessors and successors: Royal Radar Establishment and predecessors: Registered Files. Installation of A.I. in Mosquito aircraft.

  Held by:	The National Archives, Kew - Ministry of Aviation
  Date:	1940 - 1948
  Reference:	AVIA 7/971
  Subjects:	Research

• A.I. MK X: installation in Mosquito aircraft

  Ministry of Aviation, predecessors and successors: Royal Radar Establishment and predecessors: Registered Files. A.I. MK X: installation in Mosquito aircraft.

  Held by:	The National Archives, Kew - Ministry of Aviation
  Date:	1943 - 1944
  Reference:	AVIA 7/2430
  Subjects:	Research

• A.I. MK X: installation in Mosquito aircraft

  Ministry of Aviation, predecessors and successors: Royal Radar Establishment and predecessors: Registered Files. A.I. MK X: installation in Mosquito aircraft.

  Held by:	The National Archives, Kew - Ministry of Aviation
  Date:	1944 - 1945
  Reference:	AVIA 7/2431
  Subjects:	Research

• A.I.S. prototype fitting on Mosquito aircraft

  Ministry of Aviation, predecessors and successors: Royal Radar Establishment and predecessors: Registered Files. A.I.S. prototype fitting on Mosquito aircraft.

  Held by:	The National Archives, Kew - Ministry of Aviation
  Date:	1941 - 1944
  Reference:	AVIA 7/1093
  Subjects:	Research

• Installation of prototype A.I. Mk IXA in Mosquito aircraft

  Ministry of Aviation, predecessors and successors: Royal Radar Establishment and predecessors: Registered Files. Installation of prototype A.I. Mk IXA in Mosquito aircraft.

  Held by:	The National Archives, Kew - Ministry of Aviation
  Date:	1943 - 1944
  Reference:	AVIA 7/2025
  Subjects:	Research

• This file was originally catalogued under more than one subject heading. These headings, and details...

  Air Ministry and Ministry of Defence: Registered Files. Code B sequence (files registered 1936-1953). (Code B, 5/6): Fitting of Mosquitoes with AI Mk VIII. RADAR AND RADIO COUNTERMEASURES (Code B, 61): A.I. Mk VIII: fitting of Mosquitoes.

  Held by:	The National Archives, Kew - Air Ministry and Royal Air Force records
  Date:	1942 - 1943
  Reference:	AIR 2/7731
  Subjects:	Air Force | Armed Forces (General Administration) | Radio and television

 

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