Looks like somebody added this as a precursor to the 2 pounder.
I would bet the same gun as the Vickers Medium (Unit 125) on a land cariage. 3pdr is 47mm, and plenty were available as it is a naval standard (Hotchkiss) from WW1 and before.
This article describes HMAS Hobart landing one on land carriage as an impromptu ATG:
HMAS HOBART (I)
Quote:
HOBART also landed a QF 3-pounder Hotchkiss gun for service with the Army as an anti-tank gun. A volunteer crew of three from HOBART accompanied the gun. Fighting a rearguard action, these men were at first reported ‘missing, believed killed’ but were later rescued unharmed from Italian hands when the British captured Massawa in April 1941.
|
However I can find no real precursor to the 2pdr ATG in a web search, and Hogg does not mention one either.
This looks like something the OOB design team put in as a "filler" - I certainly did not add it
! - I think prior to 1936, the UK army would have only AT rifles, or 15/18 pdr field guns extemporised as ATG, perhaps.
Cheers
Andy