Karabiner 31(K31)

One of the motivating factors for getting a Curious and Relic license was to order a K31 Swiss rifle from AIM. I first got familiar with Swiss rifles back in High School when my dad bought a 1911. The straight pull bolt interested my curiosity. But the $24.00 box of Norma ammunition prevented me from ever using it. When I first become interested in collecting surplus rifles one of the first rifles that caught my attention over even the Enfield was the K31. Within a week of receiving my C&R license my order for a walnut stocked K31 was placed with AIM. Not only was it a thrill to have a firearm sent right to my door but to open the box to a very fine built firearm was a bigger one. Removing the cosmoline from the metal reviled bluing close to new, every thing was in very perfect working order. The walnut stock was typical of what I have read, nice color but dings on the butt stock. This one came with the name tag underneath the butt plate.

History

The K31 is basically the third generation of the Schmidt-Rubin straight pull rifle used by Switzerland. The previous being the M1889 and the M1911.

General

Everything that is said about the K31 is true. Fine craftsmanship and unreal accuracy are the key notes of this rifle. Being around mausers and a few Enfield all my life the bolt operation on the K31 is at first a little strange. But, after working the clockwork smooth action a few times any oddity is erased. The bolt operates simply by pulling the bolt hand back and pushing it forward to chamber a round, no lifting of the bolt handle is needed. Coupled with a detachable magazine, chambering is very reliable. Incorporating a rear leaf sight with a generous half moon shape along with a front blade gives it a good sight system. Overall balance is very good, not to much weight in the front or rear. The K31 shoulders very well and getting focused on the sights is relatively easy.

Chambering

The K31 is chambered in 7.5x55 Swiss which is very generous in recoil and gives fine ballistics. While some will argue that the 7.5x55 round is equal to 308 Winchester in ballistic its not totally true. Hornady’s commercial ammunition has a 165gr bullet going 2730fps which is identical to 308 Winchester. Any published reloading data that I found between the two has the 308 besting the 7.5 by 100-200fps. That puts it just above the 300 Savage, either way it a fine cartridge ballistically. Overall length is 3.05 which is .05 longer than the 308. This put the 7.5x55 right in the short/medium length cartridge class.

Because this round uses .308 diameter bullets reloaders can enjoy a wide variety of options. I first tried 180gr Sierra Gamekings with great results. I also tried 150gr Speer but my K31 did not shoot them as accurate as the 180gr Sierras.I found IMR4350 to be a good powder for this rifle. I reformed 284 Winchester brass which can be a choir. The initial resizing is most important because you must change the shoulder angle otherwise the bolt will not close all the way. Once the brass is reformed the first time it is business as usual. One thing to remember also is that the K31 have a very tight chamber so overall length is very important.

Beyond the range

This rifle has everything you can ask from a deer rifle. But at 9 pounds it is not something I would do a lot of stalking with. The shorter length (approx 44") would make it at home in a deer blind. With the chambering being close to the 308 Winchester ballistics the potential for bigger game is there. The is a couple no-drill scope mounts which can allow you to better take advantage of the down range ballistics. With good optics I would consider this a great whitetail deer gun out to 300yards.

Official Review from a unofficial person

If you do not have one, get one. Switzerland was a neutral country so they never were forced to have to kick out tons of rifles in a short time. This has raised the quality considerable. Second because these rifles never seen a battle they are in great shape, minus some dents on the stock. Third the superior accuracy that is achieved by this rifle is unreal. Expect 1" groups as a norm with surplus or reloads. If there is a shortcoming of this rifle it is the safety, which can be mastered with a little practice. Either way this is one rifle that should be a part of everyone collection.