My personal view is that they should go to 35mm, because it has greater range and hitting capability than the current 25mm, so has the reach and power to neutralise targets armed with 30mm guns or less. However the Canucks didn't upgun staying with the 25mm.
I think that they should be fitted with a sighting system such as or with similar capabilities to the
SAAB UTAAS Tank and Anti-Aircraft System - Universal Sight and Fire-Control System. This capability would give the NZLAV an AAA capability which at present is a sadly lacking commodity in the NZ Army armoury. The 35mm gun combined with this sighting system would be quite formidable against helicopters, low flying aircraft and RPAS.
Also during the MLU, the vehicle turrets should be fitted with the studs and electronic connections to enable the easy mounting and dismounting of vehicle box launchers for the FGM-148 Javelin Anti Tank Guided Missile and SHORAD missile such as Mistral or FIM-92 Stinger. The NZ Army already uses the Javelin as a man portable missile and Mistral as MANPAD (MAN Portable Air Defence). These two additions could be FFBNW on all the turrets with the weapons being mounted when required. These weapon systems would give the NZLAV a reasonably formidable capability for a relatively low cost.
Mobile guns are able to stop, shoot and scoot very quickly, literally within a minute or so and before counter-battery fire can impact upon their position. They are also easily able to keep pace with infantry forces and to support the infantry with direct or indirect fire. It is this ability that enables them to be employed across the full gamut of artillery roles from anti material / personnel to anti armour. In the NZ context a Mobile Fire Support System (MFSS) battalion would not normally be expected to attack an armoured division on its own because that is not within its concept of operations (CONOPS). However a wheeled MFSS based on the current NZLAV would provide a full range of fire support for the infantry.
The US Army M1128 LAV based 105mm Stryker MGS uses a remote control automatic 105 mm gun with 18 rounds loaded into the vehicle magazine. However there have been difficulties encountered with vulnerabilities including protection for the gun pod, commanders’ weapon station and the 105mm ammunition, which led to degraded capacity and unreliability. The restriction imposed by the US Army upon the Stryker MGS was that it had to be air transportable in the C130 aircraft hence its weight, width and height were restricted by the C130 design parameters.
A 105mm gun turret such as the Cockerill CT-CV 105 HP which is specifically designed for medium or light armoured vehicles would be more practical and less risky than the US M1128. It is advertised as being easily integrated into existing vehicles. The turret itself is armoured and can have extra armour added on as required. General Dynamics Land Systems (GDLS) Canada has awarded a €3.2 billion contract to CMI for Cockerill turrets for the multibillion dollar Saudi armoured vehicle contract. This contract includes the Cockerill CT-CV 105 HP turret as well as Cockerill medium calibre turret systems. From 2003 – 2006, GDLS, who build the LAV, and Denel (of South Africa) integrated the Denel 105mm howitzer with the Stryker, for a US Army light Self Propelled Howitzer (SPH) program. This program only progressed as far as prototype stage and then was replaced by the M1128.