Abraham Gubler said:
What does this have to do with a secret project? There are plentiful web forums for proposing and discussing force structure and potential weaponry.
My hope was to unearth some past, present or future projects for mobile firepower in light of recent conflicts, so very much in the spirt of this grounp.
The U.S. military has come to the realization that sophisticated guided weapons are not always a very cost-effective way to deal with threats (using a US$70,000 Milan anti-tank missile to deal with a "specialized" machine-gun armed pick-up truck, for example). The Navy's Spike missile project (not the Israeli one of the same name) is intended to provide a small guided missile for use against everything from bunkers to vehicles to helicopters for just $5,000 per round. It's not just a question of cost--one disposable rocket and launcher is far handier than a light cannon, but 100 rockets are less handy than a light cannon and 100 rounds of ammo and the rockets cannot generally be used for sustained or indirect fire.
Sometimes the old school solutions are worth re-examining in light of experience. A modern ultralight 75mm howitizer, perhaps with a steel-lined carbon-fiber tube and all-digital assisted aiming, might be a very useful additon to the toolchest.
Another example, the French "trench gun" Canon d'Infanterie de 37 modèle 1916 TRP (U.S. M1916) used by U.S troops in WWI and a bit in the Pacific in WWII. It was far too small to do anything against armor but it could ruin a dug-in machine-gunner's day from a mile away and weighed only 108 kg combat-ready. A modern version on wheels, even lighter, with digital fire control and a shield for the crew, could be very useful even in urban combat (no backblast, sustained fire).