The Karabiner 98 Kurz, or as it is referred to in-game, Gewehr 98k, is a World War 2-era weapon, and a sniper rifle. The gun is just a "Carbine" version of the Gewehr 98 (the 'k' designation stands for "Kurz", or German for "Short"). The G98 remained Germany's main service rifle for more than half a century, with few modifications. The main difference is that traditional Gewehr 98 in 1914 was about 50 inches long - the Gewehr 98k is simply cut down to a more modest size by seven inches.
Otherwise, the rifle is essentially identical to the traditional World War I-era Gewehr 98. Some slight, and evidently distinguishing differences are the turned down "sniper" bolt handle, the shortened size, and most importantly the sniper scope mounted on the weapon and camouflaged with a bit of burlap.
It's available in very large supply, strangely, as most German guards seem to be equipped with them (one would think snipers would be the smallest proportion of troops, especially considering the cost of optical scopes and training), and fewer use the MP-34 Submachinegun. Given that the World War II segment takes place primarily in a concentration camp, and in surrounding German occupied territory, there are no other opponents and weapons from different nationalities to choose from.
- The scope used on the M98k is a low-powered 1.5x scope used for snap-shots. They were originally designed for the StuGew-44.