If you have a K-31 with a poor bore --------

[SwissShooter]

I had one that was 99% outside but had serious pitting. Replacement barrels are rare and expensive. I spoke with JES and he agreed to rebore it to create a 9x55 Swiss (really .357). He did a 3 groove and it works perfectly. I "hogged out" some 358 Winchester dies to leave the neck sizing and seating parts intact. Works perfectly. The Swiss case has more capacity than the 358 Winchester and, as we know, from Swiss websites, many K-31s have been rebarreled to 50 K+ (243/308/25-06 etc) cartridges with no ill effects. My interest is not in hot-rodding it, rather cast boolits. Initial results w/220 gr Lee PCed and 250 gr Speer were good. Now have it scoped and waiting for range to reopen.

[waksupi]

I'm amazed you found a K-31 with a bad bore!

[SwissShooter]

Until I bought a borescope, I believed the same. Many rifles that look great when you peer down the bore look "bright and shiny". I've owned 8 Swiss rifles and all had some degree of pitting or erosion. Most will shoot just fine with J-word bullets. The Lyman bore scope is inexpensive and IF you only use it in a clean, dry bore it works fine.

[djryan13]

Interesting

[Silvercreek Farmer]

Nice! What twist rate did you go with?

[M-Tecs]

http://castboolits.gunloads.com/show...g-my-K31-Swiss

[SwissShooter]

1 in 14 as he suggested.

[RU shooter]

35 Whalen data would be close as the 7.5 and the 06 have about the same volume according to one of my reloading manuals forget which one at the moment

[M-Tecs]

The 7.5 x 55 Swiss is very close to a 30/284. Lots of shooter just neck the .284 Win up to 30 Cal and use it in the K31's. The rebated rim still works so case volume is much closer to the 35 Whelen than it is to the 358 Win.

https://forums.gunboards.com/showthr...s-from-284-Win

[SwissShooter]

7.5x55 cases are easily found by Privi and Norma. No need to reform. For my use, as I don't intend to hunt with it,
I'll be loading closer to 35 Remington levels than 35 Whelen levels.

[SwissShooter]

Another pic of the 9x55.

[M-Tecs]

7.5x55 cases are easily found by Privi and Norma. No need to reform. For my use, as I don't intend to hunt with it,
I'll be loading closer to 35 Remington levels than 35 Whelen levels.

My point is the case volume is much closer to the 35 Whelen than the 35 Remington when selecting load data since data for a 35/7.62 x 55 Swiss is very limited. Case volume of the 30/06 and 284 are both 66 grains of water.

[SwissShooter]

You are correct. I suppose I could take a 308 Ruger No 1, get a rebore and rechamber, maybe even "Ackleyize" and have a powerful 35 caliber rifle. Not the point of my effort. Just wanted to clean up a nice K-31 to shoot with cast boolit pooper loads. Besides I have a Ruger 1B JES 35 Whelen that will rock you with full house loads.

[M-Tecs]

You are aware that there a lot of light load cast bullet 35 Whelen data available that is direct match for your case volume??????

[725]

Love it when a creative mind saves compromised rifle. Good going.

[SwissShooter]

You are aware that there a lot of light load cast bullet 35 Whelen data available that is direct match for your case volume??????

Of course I am. But for light loads there is material difference. As someone once noted here: "10 gr of Unique works with everything." (largebore riflewise)

[M-Tecs]

Of course I am. But for light loads there is material difference. As someone once noted here: "10 gr of Unique works with everything." (largebore riflewise)

What is the material difference?

7.5x55 cases are easily found by Privi and Norma. No need to reform. For my use, as I don't intend to hunt with it,
I'll be loading closer to 35 Remington levels than 35 Whelen levels.

The universal load of 10 grs. Unique doesn't come close to 35 Rem levels. Velocity will be in the 1200 to 1300 FPS or less with 220 grain cast.

[SwissShooter]

Okay M-Tecs, you're right and I'm wrong. ----- except that a 220 gr boolit at 1300 fps has more ME than any 357 magnum load and will work just fine for 50 yard plinking.

[M-Tecs]

It's not about who is right or wrong. We are all here to share information. Either to learn, to help others or both. Incorrect information benefits no one.

[SwissShooter]

In any case, I brought a tired K31 back to life and may have even invented a new wildcat. The rest is "nice to know".