Karabiner 98k (Remastered)

The Karabiner 98k is a controlled-feed bolt-action rifle based on the Mauser M98 system. Its internal magazine can be loaded with five 7.92x57mm Mauser cartridges from a stripper clip or one-by-one. After loading, the empty clip is ejected when the bolt is closed. The straight bolt handle found on the Gewehr 98 bolt was replaced by a turned-down bolt handle on the Karabiner 98k. This change made it easier to rapidly operate the bolt, reduced the amount the handle projected beyond the receiver, and enabled mounting of aiming optics directly above the receiver. Each rifle was furnished with a short length of cleaning rod, fitted through the bayonet stud. The joined rods from 3 rifles provided one full-length cleaning rod.

The metal parts of the rifle were blued, a process in which steel is partially protected against rust by a layer of Magnetite (Fe₃O₄). Such a thin black oxide layer provides only minimal protection against rust or corrosion, unless also treated with a water-displacing oil to reduce wetting and galvanic corrosion. From 1944 onwards Phosphating/Parkerizing was introduced as a more effective metal surface treatment.

Sources: 
Wikipedia