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 15mm BESA case...finally 
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Joined: Wed Dec 31, 1969 8:00 pm
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Interesting, Tony; would that .661 have been chambered in an upsized Vickers, then?


Thu Apr 12, 2007 4:10 pm
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Joined: Wed Dec 31, 1969 8:00 pm
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Post .661
Essentially yes.

Regards
TonyE


Thu Apr 12, 2007 4:13 pm
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I don't know. I only have two sources of information about the gun, and they seem to be contradictory. One is Campbell's brilliant "Naval Weapons of World War 2" (now back in print) which states that a six-barrel mounting was ordered in 1935 but cancelled in 1938; the ammo fired an 85 g bullet at 952 m/s; the gun was expected to be capable of 300 rpm; and that it was loaded via feed rails rather than belts. I find this last statement very odd, and since I recall Herb Woodend saying that he had a round with belt links attached (Herb was more interested in belt links than ammo, as many will recall) it seems suspect.

Vickers didn't just make the usual Maxim-type mechanisms. The also made the gas-operated Class K in .303, and pictures of the rare Vickers 25.4mm naval AA gun, also dating from the mid-1930s, show what appears to be a gas-operated, air-cooled design - with a box magazine (there's an illustrated article on this gun and ammo on my website).

I understand that the Vickers archives are now in the library of the University of Cambridge, but they didn't respond to my enquiry...


Thu Apr 12, 2007 4:20 pm
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Does anyone know exactly why the UK spent so much time, energy, and money developing and fielding all of these different rounds (50 Vickers, 50 Vickers SR, 50 Vickers D, 661, 15mm Besa, etc., etc), instead of standardizing on one that could do most things reasonably well? Was it inter-service rivalry, "not developed here" syndrome, or... ?


Thu Apr 12, 2007 6:05 pm
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My understanding goes something like this:

.5 V/580 (12.7x81) = developed in conjunction with the military 1917-24, to meet a specification for a tri-service HMG round.

.5 V/565 (12.7x81SR) = private venture by Vickers for export purposes, reportedly to get around official objections to exporting the latest official ammo (i.e. the rimless .5V)

.5 Class D (12.7x120SR) = private venture by Vickers to address concerns that the .5V might not be powerful enough to meet customer requirements.

.661 Vickers (16.8x149SR) = RN specification to develop a much more powerful AA gun to replace the .5V (the Class D evidently wasn't enough)

15mm BESA (15x104) = off-the-shelf purchase by the army in c.1938 to acquire a light AFV gun which was substantially more powerful than the .5V, to obtain better penetration. I suspect that there might have been an element of "buy Czech" here, simply because the army had already adopted the Bren and they bought the 7.92mm BESA at the same time - they were obviously very impressed (and rightly so) by the Czech gun designers.


Thu Apr 12, 2007 9:27 pm
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Post 15mm BESA case...finally
Out of .661 Vickers and 2x110RB Oerlikon, which offered better performance? Surely necking up the .661 (16.8mm) to 20mm would have produced a formidable AA round for the time. I wonder if it would have been practical to re-barrel the Vickers type gun that the .661 was designed for to 20mm? Surely the limitation for the original .661 was the amount of HE that could be contained in the .661 Projectile.


Fri Apr 13, 2007 3:55 am
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I have some other info about the .661, in that it was felt that it couldn't be got into service before 1942. Obviously, redesigning it to take 20mm shells would take even longer, and the velocity would be reduced accordingly.

The Oerlikon S was well-proven (the British had been playing with them since the late 1920s), faster firing, and available pretty well immediately. It was also much simpler to install, as the single mountings were very light. I think that the RN was getting worried by then, and wanted something quickly.

Incidentally, there was another Vickers HMG I missed from that list, and that was a 16mm gun which was in competition with the 15mm BESA. However, I can't recall offhand even seeing a photo of that round.


Fri Apr 13, 2007 4:09 am
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Post 16mm
Here is a drawing of the 16mm Vickers, but like TonyW I have never seen one.
Image

Whilst we are talking about little known British rounds, let us not forget the .5 BSA Observers gun, the 13.2mm BSA A/T rifle, the 13.5 x 104mm Kynoch MG, .8 Elswick, .9 EOC etc!

Regards
TonyE


Fri Apr 13, 2007 11:01 am
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Post 15mm BESA case...finally
Interesting drawing. Were the guns / cartridges ever actually made or just designed?


Fri Apr 13, 2007 11:07 am
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Post 16mm
Certainly the ammunition was made, as Kynoch made at least one batch in April 1938. I suspect another batch was made as the drawing I posted shows an amendment to the bullet envelope compared to a previous drawing I have.

I have no reason to believe that the gun was not made as it was certainly offered to the army as a tank MG, but in a quick search of the SAC Minutes I have I could not find it mentioned. However I do not have a complete set of SAC minutes or OB Procs.

Regards
TonyE


Fri Apr 13, 2007 11:30 am
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Post 15mm BESA case...finally
So somewhere out there, there must be a complete 16mm Vickers cartridge, bullet or case. Would the pattern room have an example?


Fri Apr 13, 2007 11:38 am
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Post 16mm
I don't know if the Pattern Room have an example of the gun, but I do not remember seeing one. It was a private Vickers initiative so they probably do not have one . I will check out of interest. I am sure they do not have a round.

Regards
TonyE


Fri Apr 13, 2007 12:35 pm
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