



By Diego Cesarei

The K31and the P210 are for me the most iconic products of the Swiss weapon industry. All in, the K31 screams “Swiss Made.” The mechanics are exquisite yet simple, it’s sturdy, but elegant and the accuracy fits the stereotype of everything made in the Alps republic. Thankfully, one thing about the rifle that’s not Swiss is the price. I paid 150CHF for my 1941 K31 and a quick on-line check confirmed that the US price is pretty much the same making it a super-affordable bolt action . . .

Wait a second, did I write “bolt action”? The K31 is in fact not a bolt action but a straight pull rifle. The shooter just needs to pull and push the charging handle horizontally in order to operate the rifle. Typically a straight pull rifle is faster than a normal bolt action, but bulkier and more expensive to produce.

I bought the gun by happenstance. I was basically waiting for my Arsenal Strike One that wasn’t going to arrive any time soon and my “gun buying permit” was about to expire. Well I couldn’t let that happen, so I entered the closest gun shop and used my permission slip on the K31 because it just seemed like the right weapon to celebrate my recent relocation to Switzerland.

For the first year or so I shot it with open sights, at 300 meters from prone position (most Swiss gun clubs only allow this kind of shooting with service or former service rifles) and I started liking the rifle/caliber a lot. The results were so good that it made me wonder how good it could perform with a decent scope and a few well-placed modifications. The rifle, like a lot of other battle rifles of the same era, has a lot of potential and enough flexibility to go from hunting to SHTF weapon without flinching.

That said, a few considerations are needed. It would have been foolish to spend much more on a scope and accessories than what I spent on the rifle. Then again, it would have been a pity to take a great old gun like this and add cheap accessories. I also didn’t want to lose the gun’s fighting spirit. The K31 is no hunting rifle, it was the weapon of the Swiss militia during WWII. Yes, I know that it didn’t see much action back in the days, but it was still built for the purpose of defending one of the oldest democracies on earth, a country where each citizen is a soldier who brings his gun home after the service to be ready to repel any would-be invaders.

But what actually needed to be changed on the K31? How do you convert an old, accurate military rifle into a 21st century weapon system on a shoestring?

The K31 was designed for the needs of a better generation than the current one. Let me digress and state an evident truth: since WWII the progressive “pussification” (as Nutnfancy would say) of the western average male is a matter of fact, what our grandfathers (and probably our grandmothers) lived through during the war is simply unconceivable for the average contemporary man.

This is to say that to my standards, the 7.5×55 Swiss round is quite punishing on the shoulder and the K31’s steel butt plate doesn’t help mitigate its kick at all. So a rubber butt plate and a muzzle brake were the first items on my list. Attaching a rail on top of the receiver would make the open sights unusable and make it impossible to employ stripper clips. The rifle would also eject casings straight against the scope. So an offset battle ready (i.e. not clamp on) rail and a decent, yet affordable scope were next.

The K31’s two-stage trigger is OK and doesn’t need modification. Although every K31 has a sort of pillar bedding, the barrel isn’t free floating so modifications of the stock and/or bedding of the action qualified as last point in my list.

Most of the accessories I used are from the Swiss retailer of a Montana-based company called, appropriately enough, Swiss Products LLC. I think they offer the best solutions for the money and I’m very happy with what I got.

The threaded (14×1) muzzle brake is definitely effective. The company states that it should decrease felt recoil by 23%. How they came up with that precise number I don’t know, but it does the job. The quality is excellent and once installed it blends in perfectly. They offer a clamp-on version as well that’s slightly more expensive, but I felt that the threaded version was definitely the most solid alternative.

Also from Swiss products is the “drill and tap scope mount”. Again we have good quality at an affordable price. The rail is mounted on the receiver with three screws making the thing rock solid. It’s shaped to match the receiver round side making it more difficult to fit it incorrectly i.e. not parallel to the bore. The rail is offset to allow the use of stripper clips and iron sights. The downside is that when carrying the rifle the scope bumps on your back or ribcage and the gun is a bit off balance. A Piccatinny rail would have been more versatile than the dovetail but, so far, it has worked OK for me. Something that I really would have preferred is for the rail to be a bit longer in order to have more mounting options for the perfect eye relief.





Last part I took from Swiss Products is the recoil pad adapter. The butt of the K31 isn’t straight but slightly curved, so fitting a recoil pad would have required some modification. Considering that I appreciate a curvy butt as much as the next guy, but I didn’t think I was up to the job (and I don’t have the proper tools). Once the adapter was in place I added a large Hougue rubber butt plate that was resized to fit the stock.

I knew that finding a good yet affordable scope would have been the most difficult part of my project. It had been 10 years since last time I was in the market for a scope and I had no idea where to start. So I was relieved when Tim of the Military Arms Channel enthusiastically reviewed a couple Primary Arms products and I quickly decided to give them a try myself.

After getting most of the above parts I contacted Primary Arms to place my order. Imagine my disappointment when I found out they don’t ship internationally. Thank God the internet has the answer for almost everything. I started checking reviews, considering my alternatives and my final choice was for an Optisan Viper 10×44. It’s Chinese made (as are the Primary Arms scopes), but in my opinion it offers the best quality for the money in that price range. Most of all, it’s available worldwide.

Before giving more in depth commentary on the scope, I need to spend a bit more time with it. I will eventually write a dedicated review, but for now all I can say is that I’m happy so far. Obviously it doesn’t have the same optical clarity of a top notch European optic but the difference to me isn’t worth the $1800 or so one would cost me.

Another not so easy decision was what to do with the stock. Again destiny (in the form of issues in the international payment and shipping system) determined the choice for me. While Boyds’ makes very nice stocks, I couldn’t seem to process a foreign payment for one, meaning a custom stock was out. So having the barrel threaded, the scope mount attached and a scope on its way, I decided to spend my time customizing the original stock rather than on the phone arguing with my bank or Boyds’ customer service. I ended up cutting the hand guard shorter, adding three ventilation holes on each side, adding the butt plate and adapter, remove as much material as needed for a floating barrel, adding a bit of McNett Camo Form where needed…et voilà!

Before I knew it, I was zeroing my scope in a 300 meter training range in central Switzerland that’s entirely build inside a mountain (link just in German).

Other mods I would like to add: Mojo peep sights, a bipod, extra/modified magazines (eventually stripper clips from Swiss Bianco). Considering that I went for a fixed 10X scope, the Mojo sights would allow me to engage close-range or moving targets quicker than using the scope or the current fixed sights. I haven’t Mojos’ yet because on this side of the Atlantic they retail for almost the same price as my scope. Depending on what the intended use of the gun is, in general, I would suggest you to consider the Mojos’ for your system.

For some reason, extra magazines for a K31 retail for about one third of the price I paid for the rifle. I will eventually buy a couple of them anyway or maybe buy an entire rifle to cannibalize on spare parts. Apparently there are modified 10/12 rounders (two magazines welded together or modified FASS 57 magazines), but I can’t seem to find a maker (if you are one, please insert your email address in the comments below). US-based Swiss Bianco published a video on newly manufactured stripper clips that I would like to have, but they are not available yet.

The result: the gun shoots like a laser. It is reliable, easy to operate and maintain, there is abundance of ammunition and spare parts, and it doesn’t look super tactical or in any way more lethal than it is. I think I successfully converted a 70-year-old battle rifle into a very good all around weapon keeping the overall costs below $600 (excluding gunsmith fees which will vary depending on where you are and what you can do on your own). Most of all, I had a lot of fun doing it. I’m planning to use it in sniping competitions that are becoming more and more popular here in Europe. Given the time, I’ll I’ll let you know how this old gentleman fares against competitors with equipment costing them ten times more than I’ve spent.