Introduced in 1955, the K31/55 takes the rugged and reliable K31 receiver and upgrades it with a heavy muzzle brake with integral bayonet lug, ergonomic stock with swiveling steel bipod, and a pair of claw bases machined directly into the left side of the receiver. Matching numbers are present on the receiver, bolt, "Zf.Kar" marked magazine, scope and scope case. The 3.5x fixed power scope has a one-piece steel body/mount construction, marked "4632/KERN AARAU/V=3.5/(field of vision symbol)=75 0/00" on the top, and the case is finished in a dark gray and unmarked except the serial number on the lid. A pair of right handed grasping grooves are milled into the stock forearm, with a checkered pistol grip, brown leather sling, and a steel buttplate.

Excellent, with 98% plus of the original blue finish, showing a few light handling marks. The stock is also excellent, with a scratch on the right side of the butt and a few dings and scuffs overall. Optics are crisp, and the rifle is mechanically excellent.