American Stryker wheeled infantry vehicles are getting an upgraded version of the RWS (Remote Weapon System, a .50 caliber machine-gun that can be fired by an operator inside the vehicle.) The RWS is made by a Norwegian firm and, without the weapon, weighs 220 pounds. You can mount a machine-gun (usually .50 caliber) or an automatic 40mm grenade launcher on the RWS. While the troops have liked the RWS, this first intense combat use of the system has revealed problems. The extreme heat in Iraq would sometimes cause the system to freeze up. After several fixes, the problem finally went away. Although RWS is supposed to be able to fire accurately while the vehicle is moving, this often doesnt work, especially when the Stryker is moving cross country. 

While the troops liked the thermal sight on the RWS, they also found it difficult to use because of the low resolution. The RWS uses a less capable thermal sight than is found on other armored vehicles, and troops who have used the more capable thermal sights on the M-2 Bradley could not help but notice the difference. Troops also want a range finder. But the troops find much to like about the RWS. It is generally pretty accurate, especially with the daylight camera. And you only have to be manning a vehicle machine-gun the conventional way, with your head and shoulders outside the vehicle, to really appreciate the RWS. The Stryker vehicles come under fire a lot, and the bad guys know they cannot knock out exposed machinegunners if an RWS is encountered. This vulnerability was what led to the development of the first RWS, during World War II, by the Germans. That first version used a periscope and manual controls, and was installed in the Hetzer Assault Gun. The Hetzer was a widely used turretless tank (called an assault gun), and spent most of its time supporting infantry units. But the Hetzer, like most armored vehicles, had a 7.92mm machine-gun, mounted in front of a hatch on the top of the vehicle, that was operated by a crewman. The casualty rate for these crewmen was very high, and that led to the development of this first, crude, RWS. 

Similar systems were used after the war. In the 1950s, Sweden had remote control 20mm cannon on their APCs. The original German version had problems that persist in RWS to this day. That is, the field of vision was not as good as what a persons eyes alone had. Reloading was slower, and the RWS itself took up more space than a gun operated just by a soldier. 

But like most modern weapons, developers keep at it, taking feedback from the troops and tweaking the system until it works quite well. Such is the case with the current RWS. More systems like this are expected to enter service as the essential components, like thermal imagers and advanced stabilization systems, become cheaper and more reliable.