Vickers are going to suggest that; they don't see any other way of getting a decent HE round. IIRC, its not so much the shell is longer but less propellant means to can put in more HE. The AT guns will just have the AP rounds, though.The new HV 6lb is interesting. Are they going to have an HE round firing a longer heavier shell at a lower muzzle velocity. Yes this takes more training and duel sights but it gives the little 57mm gun much more bang against non armoured targets and has the added benefit of increasing barrel life.