Vickers S-gun or 40mm bofors?

[fert]

Hi,
please help me to ID this AP-T shell, marked APJC12 42 it measures in lenght 155mm
browsing the forum I found a couple o topic about the Vickers S-gun. Seems the S-gun AP it's 164mm, is the lenght the same for all Mk?



http://www.bocn.co.uk/vbforum/threa...-40-X-157R-tank-buster-round?highlight=bofors
http://www.bocn.co.uk/vbforum/threads/31093-RAF-20mm-Hispano-and-40mm-Vickers-S-help

otherwise, it could be a bofors AP-T? anyone has drawing and color code please?
thanks in advance,

best regards

 

[rcaf53]

My money on the Vickers S gun
Frank.

 

[Vasco Da Gama]

As usual this is not an easy story and the information offered is from a book, The Guns of the RAF 1939-1945, by G F Wallace published in 1972. This is a first hand account as the individual worked directly with Wing Commander Dru-Drury who did the air firing trials for the S gun and then went out to command 6 Sqn in the desert for their first operational use.


First point is that he was unhappy with the use of the Royal Navy 2pdr cartridge case (40x158) the Vickers made cases were of harder brass than cases made by Kynock. The softer Kynock cases had their rims torn off by the extraction forces in the S gun, requiring oiling of the ammunition to cure.


The first projectile mentioned was a HE round longer than the RN ammunition, made by Vickers. The first AP round AP Mk1 weighed 2 pounds 7oz. This was replaced by the AP Mk 5 weighing 3 pounds and gave a 9% increase in performance.


It would appear that 2 practise rounds were produced, the first replicating the HE weighing 1 pound 13 .75oz. A second Practise round was produced to replicate the AP round and weighed 2 pounds 7oz.

 

[Tony Williams]

The S-Gun round is on the right of this pic. I think that both the Mk 1 and Mk 5 had the same external appearance, the difference being that the Mk 1 had an internal cavity which was reduced or filled in the Mk 5.

Here's another pic of the 3 lb S-Gun round next to the experimental Littlejohn loading. AFAIK, not one of those survives.

 

[Quatermass]

Fert, dimensions and profile match those of a Bofors AP.