K31 "Modification": Improvement or Botching?

[Shane Tuttle]

I read in another thread a few days ago in regards to converting a K31 from it's original chambering of 7.5x55 Swiss to a .308Win. WHY?!

I can only think of one reason. The availability of reloading components such as dies is not as easy to locate as .308. IIRC, the only die set to make the true configuration is Redding. Quality ammo is available such as GP11. I don't know if there's good hunting ammo or not for it.

To make it clear, every gunowner has every right to do whatever they want to their own firearms. Right now, K31s are pretty inexpensive. But why, IMO, botch a perfectly good piece of history? Aren't there plenty of used rifles on the market to modify to your liking instead? I just don't see ruining a rifle that's very accurate already. Also, how many milsurp rifles have gone from a dime a dozen and available everywhere to costly and uncommon? Any modifications to these milsurps surely drops the value to almost nothing.

What say you? What am I missing here? Am I not seeing the big picture? How in the world is a .308 cartridge so much better than 7.5x55 to justify the change?

 

[garryc]

What say you? What am I missing here? Am I not seeing the big picture? How in the world is a .308 cartridge so much better than 7.5x55 to justify the change

Silly is what it is. You would need a new barrel first off, threaded chambered and installed. Then the fact is the 7.5 case is larger diameter than the 308, getting it to feed through the swiss magazine might be a chore. A lot of new rifles would fall well below the price of such a conversion.

 

[wdelack]

These are just one of the gunsmiths to offer such a service:

http://www.lprgunsmith.com/index.htm

I think it might have to do with people whom like the straight pull bolt action design but want it in a different caliber.

 

[garryc]

Straight pull bolt with no useful saftey. How about an american straight pull, like a Remington 7600

 

[amd6547]

Remington 7600 are OK rifles...K31's are great rifles.
My K31 is the most accurate rifle of all the rifles I own or have owned. It will put 6 rounds of GP11 service ammo into one inch at 100 yards.

 

[Kreyzhorse]

I read in another thread a few days ago in regards to converting a K31 from it's original chambering of 7.5x55 Swiss to a .308Win. WHY?!

I'm baffled. My K-31 is a great shooting rifle very accurate rifle. I don't understand why any one would change one.

 

[Jimro]

GP11 ammo is just one loading. And if your K31 doesn't shoot that load well, or the barrel is worn out...

Then rebarreling to 308 Win makes quite a bit of sense if you need to rebarrel. Lots of components, commercial loadings (hunting, match, and plinking FMJ), and even multiple sources of milsurp to shoot if you want to plink.

Jimro

 

[lonniemike]

Have at it. To rechamber/rebarrel the K-31 will not be cheap or easy and almost no smith will be able to do the job. Good luck on making the 308 modified K-31 an almost identical ballistic clone of an unmodified 7.5X55 K-31.

 

[Jimro]

lonniemike,

You underestimate the abilities of most gunsmiths, even amateur gunsmiths.

Jimro

 

[p99guy]

Its really not a problem to reload for the 7.5x55 swiss...Graff & Sons sells virgin brass cases for a reasonable price, the rest of the componants like powders/primers/.308 bullets are the same exact ones you would use to load .308 winchester. I load for both calibers. Since I only load for one K31, I can neck size only most of the time, just like for any other bolt action I own.
I don't own the special "K31 only" redding dies, and not in any danger of buying them.

1944 model

 

[hodaka]

I believe that the difficulty in making the conversion would be with the bolt face. The .308 is smaller so adding metal to the bolt would be necessary. If it were the other way around the conversion could be done more easily since machining off a little of the bolt would not be a big deal.

I have reloaded K-31's for several years. I use Lee dies and the only problem I have is that the bullet's need to be set correctly to length to prevent hard chambering. OAL length must be established for each brand and weight of bullet.

 

[lonniemike]

Jimro, et al, short of LPR mentioned earlier(he will slip another barrel over the old plug of the original barrel), show me or better yet start a list of professional and or amateur smiths that say that they can or will do the job. Prices would be nice too. LPR will cost somewhere in the neighborhood of $110 for the plug add $230 for your barrel you ship to him or buy one of several from Larry like a Krieger-$570, Douglas-$425, or Adams/Bennet-$323. Not bad for your $99, $199, $299, or more that you may have paid for your K-31 rifle. For maybe a $1000 plus shipping you could find a smith in Switzerland that would do the job. The factory K-31 in 308 made by WFBern(Haemmerelli) uses the original bolt face. No bolt face alteration is necessary, that will be the least of the problems encountered. Converting an 11 type isn't much of a problem but the K-31 is. Best-o-luck

 

[tulsamal]

IIRC, the only die set to make the true configuration is Redding.

Somehow I've been "limping along" for several years with my Lee 7.5 Swiss dies. Somehow both of my K-31's have done just fine with those reloads. As somebody mentioned, OAL seems to be the number one thing you need to fiddle with for success.

Gregg

 

[DoctorXring]

.

This would be a preference change. And a LOT of trouble
for little gain. And that gain would only be because you
wanted to shoot 7.62x51 ammunition in a K31 rifle.

7.5x55 is a superior cartridge design to the 7.62x51.

But that is quibbling somewhat to say even that. Both are
outstanding 30 caliber cartridges of similar ballistic potential.

"Oh bother !" said Pooh.

.

 

[Webleymkv]

I seem to remeber some company bringing in a few K-31's many years ago (when ammo was basically non-existant outside of Switzerland) and rechambering them to .308. They were quite proud of them as I remember charging a four figure price tag.