A cannon for your IFV? How about throwing the 35mm into the debate!

One stray comment started a firestorm on another post.  It went a little like this.  The Puma could arguably be called the best tracked IFV currently in production.

Then all hell broke loose.

One person said that the CV90, could mount bigger weapons, was cheaper and provided all the advantages (don't get me wrong...I like the CV90, but I get the impression that its a bit long in the tooth) of the Puma etc....

Then it turned to weapons fit.

I found this interesting.  IFV weapons evolution has been slowly but steadily creeping up.  The first gen with 25mm cannons, now the 30mm is standard but future vehicles look to add 40mm like the Brits with the ASCOD or even 57mm with the Russian Boomerang.

I don't think that's smart.

The bigger you go the quicker you run into diminishing returns.

So what's the sweet spot?

Well on this I think the USMC has it about right.  A 30mm gives you the ability to engage anything on the battlefield up to a MBT and US Army action in the first Gulf War shows that you CAN get kills on SOME main battle tanks with the 25mm.

Additionally I don't know if I want my APC/IFV fighting tanks.  A good way to see your ride go boom is for track drivers to suddenly think they're part of a tank fight.

You lose your ride and the enemy has a sideways mobility kill.  Yeah you can split up your squad and have them stuff into other vehicles but unless you're going to make the other squads temp reinforced you're gonna have issues with reforming it once you reach your objective.

So yeah.  I say go the USMC way on the Amphibious Combat Vehicle and stick with a 30mm or follow the US Army on the Stryker Upgrade and pick the 35mm....but to go larger is just vanity....but that's my opinion.  What's yours?