Sauer 202
The Sauer 202 is a lightweight bolt-action rifle manufactured by Sauer & Sohn in Germany between 1993 and 2015. The rifle was imported to the US by SIG Arms. This rifle has a modular construction which allowed easy replacement of components and caliber changes. This rifle has a modular barrel-change system allows to change between calibers easily, and was offered in a large selection of calibers. Separate magnum receivers and barrels were made which were not interchangeable with non-magnum calibers. Receiver. The standard receiver is made out of steel, but there is also a lightweight version  available made of aluminium which weighs 470 grams less. Barrel change system. The standard 202 system uses the same receiver for mini and short action cartridges, but different types of bolts. The bolts for mini length cartridges (like .223) uses three lugs, while most short action cartridges (i.e. .308) uses six lug bolts. The four main types of bolts and some of their factory calibers are: The magnum version uses a different receiver than the standard version, and some parts can not normally be interchanged between standard and magnum caliber versions. For example, the barrel tenon on the magnum receiver  is larger, meaning that barrels can not be swapped between the standard and magnum receivers. The barrel can be changed using a 5 mm hex key.