The Bofors/BAEs 40mm is a very large gun for its size. One of the key selling points for the CTS was that it, like the 30mm Rarden, is very compact, especially in teh amount of space it actually takes up in the turret. It's ammunition, though expensive, is very powerful, many times that of rival 30mm and 35mm systems which were of comparable size. As for the desire for 3P ammunition, rounds of a similar capability are being developed for the CTA and I believe are ready for service or soon will be. But once again cost becomes an issue.
Does an AFV turret have to be manned? Nowadays no, with modern sights and other optics the Commander and Gunner can be safely housed in teh better protected hull of the vehicle. Remote stations also take up less room in teh actual vehicle allowing for more dismounts in the case of an IFV, and can still be reloaded for inside the vehicle as well. Here the CTS has advantages as well as its ammunition is very compact compared to that of the the 40mm L/70, meaning you can store more ready rounds in the turret and reserve in the hull, as well as being easier to handle.
Cost has been mentioned as an issue multiple times with regards to the ammunition, but both France and Belgium seem to be happy to pay for the advantages this weapon and its ammunition bring. Surely the UK with its budget can afford to cover the cost?
If Ajax goes ahead, and as yet nothing has been said to the contrary, the Regiments equipped with it need to be just that equipped. We have the basic family members on order, but there are other variants that are needed for these units to be able to fight effectively. There are three main capability gaps:
1. The lack of a long range ATGW to provide effective overwatch and precision strike. A weapon in the class of Extractor Mk2 is needed, either mounted on an Ajax chassis or on a towed trailer like it is now. WE already have a few systems but we need additional units not just for the Ajax formation but also for the Mechanised and Motorised Infantry units. This points to the trailer mounted version to save costs.
2. The Regiments are going to need integral Short Range Air Defence against everything from UAVs to Fast Jets. The Army's current SHORAD equipped Regiments are not enough to cover the Ajax formations effectively, and a platform with a rapid firing auto cannon is needed to supplement the existing Regiments but needs to be integral with the Ajax formations. Those Regiments in the Heavy Combat Teams will have access to the Heavy Combat Engineering platforms like the Titan.
If we can build our Recce Regiments equipped as such they will be very effective formations, wherever they operate. Is the Ajax the ideal platform for the roles it will be given, probably not but we have a production contract let so we need to make the best of it.
3. Combat engineering support, these formations and the M270s of the Artillery Regiments need combat engineering support beyond the Dismounts in teh Specialist Ajax variant. at a bare minimum there needs to be a Bridge Layer capable of launching a Bridge able to support Ajax and the M270 as well as Logistics vehicles. The relatively new Terrier CET is the other engineering component needed.