Army looked at this extensively during LAND 400 Ph.2 when they had 30mm x 173mm armed Boxers shooting off against 35mm x 228mm armed AMv-35’s, with the option of incorporating the same 35mm x 228mm gun into Boxer if Army wished for same.
Army’s conclusion was the additional ammunition carrying capacity of the 30mm variants was more useful than the improved (but not hugely) range and penetration offered by 35mm systems.
Hence we have standardised on 30mm medium calibre gun systems.
Thing is though. Many of the newer IFVs arriving on the scene will have protection that approaches or exceeds STANAG 6, which as I understand it affords protection for 30 mm at 500 meters. It might be unlikely that we are facing off against advanced IFVs anytime soon, and if we are you'd hope that we were detecting and engaging them at long range but we will likely have the Redback for many decades. No one thought there would be major ground war happening in Europe in 2023, but here we are. Anything could happen in the current environment. The ability to upgrade to a larger calibre weapon should it be required to defeat rival IFVs without using missiles can only be a good thing.
For the current threat scenarios the ADF is likely to face, having more ammunition over larger calibre does make sense. Understandable why they reached that conclusion.
More broadly on the Redback decision. I think once Labour got in and Marles become the Defence minister it was a given. It does make sense to have two suppliers of amoured vehicles supplying the Army, but my personal preference would have been to have gone with the Lynx for commonality with the Boxer and give Hanwha an additional contract at the Geelong factory; to build a fleet of Amphibious Combat Vehicles based of the Tigon 6x6 to support our developing Amphibious capability.
Does anyone know if there is a plan for Hanwha develop and produce a family of vehicles around the Redback? Combat Support Variants and the like. I haven't seen anything around this. One the Lynx had going for it was it is shaping to be a family of systems and much of the development work was already done.
One can only hope that the cutback from the original number 450 to 129 is a temporary budget measure as one thing the conflict in Ukraine has highlighted (despite all the initial dripple by the uneducated that armour is dead) is that war still follows the fundamentals of war established in World War I. Troops on the ground conducting offensive manoeuvres against masses of enemy troops or fortified positions in an effort to advance forward and take control of ground. Advanced missiles, airpower, cyber and drones have yet to undo the armour-infantry-artillery triad....
Though they might shift the balance in one direction or another. Conflict it is still a war of attrition, numbers matter.
All major advances during the conflict have made use of the traditional armour-infantry-artillery triad. It remains the most effective combined arms system to conduct a structured offensive to seize territory, at least when all of the pieces work together as they should.
In the Australian context despite preparing for a maritime conflict should the unthinkable happen we will still need to confront hardened and possibly dug in enemy land forces to seize territory and deny freedom of movement on the ground to take control of strategic terrain. Missiles and ammunition will be used at an unsustainable rate in any high intensity conflict (as we have seen in Ukraine), and never will win a war alone. At some point the troops will have get their hands dirty get and flush out an adversary or occupy key areas so that the enemy doesn't. Important we give them the tools to do the job.
Anyway, both the Boxer and Redback are a quantum leap in capability great to see the ADF finally!! moving on from the M113 and ASLAV, served us well they did. DSR aside we are seeing militaries all over the world expand their armoured forces, hopefully the 129 Redbacks are the start of the ADF doing the same.
N.B: Thoughts go out to the crew of MRH-90 that when down. Hope you ok boys.