
STK Metal Storm unit + MG
and the the Redback, which appears to be the most developed. This has the barrels in a diamond pattern, and is a remote control device intended for fitting to the roof of any vehicle (it weighs 70 kg, complete with imaging sensor, thermal sensor and laser rangefinder). And - you've guessed it - they're promising airburst technology.

These are now spreading like wildfire, particularly in smaller calibres (up to 12.7mm MG or 40mm AGL), to the extent that actually having to get behind the gun and aim it by eye is now looking so 20th Century. A few are shown below.

Rafael Mini-Samson, with 12.7mm and two Spike anti-tank missiles

40mm CTWS

CTWS 40mm GPR-T

40mm CTWS APFSDS-T

The Italian Centauro, with an OTO-Melara HITFIST turret with 25mm gun
Another Centauro, this time with a smoothbore 120mm tank gun - serious firepower for a wheeled vehicle.

Another Centauro, this time with a smoothbore 120mm tank gun - serious firepower for a wheeled vehicle

The German/Dutch Boxer 8x8 with a 40mm AGL in a remote mounting (formerly a much bigger project, but now running into cost problems)

The Canadian MMEV (Multi-Mission Effects Vehicle) based on a LAV chassis, with a turret containing the existing Oerlikon ADATS air-defence/anti-armour system, plus 70mm CRV7-PG pods firing laser-guided rockets. This has been selected for the Canadian armed forces

The GEFAS mine-resistant vehicle. The front wheels are way out in front to minimise the effect of mine blasts on the occupants.