Well, I read through the old thread, and it was clear that the project had dragged on for some time. One day I was going to do this, one day that - then back to this again. A mighty tideous tread, ready to collect dust in the arcives.

So I desided to make a new thread, as things are now setteled.

This is an idea I have palyed with for about 10 years, so it is high time to see it come trough.
My first idea was to use the more popular .416, but soon it was clear that the .423 is better for different reasons. Its larger diameter will give higher velocity than the .416 with same bullet weight and preassure. The .416 can also be made on a .30-06 case with a shoulder, which a .423 can not. Some will say it has too little taper, but it has the same as the .470 Capstick, and I have no worries considered that.
It is the largest bullet diameter that can be had on the .30-06 headsize, without using a rebated rim. In a M98 it will give 5 down and one in the chamber.
So far I have calculated that with the same preassure as the .458 WinMag, it will reach 2150 fps with a 400 grs bullet, but it remains to be prooved. I am more confident to reach 2300fps with Woodleigh's 350 grs roundnose, as it takes up less space in the case.

Here is the pick of latest, still the brass is 4 mm to short, but one will get the idea. here flanked by the .458WinMag and the 10,75x68.

It is the .240 Weatherby opened up to .423. Cases CAN be made from Weatherby, like the one in the pic, but it is a lot of labour and pain, and it shortens the case considerably - 61 mm in the pic.
So I have ordered finnished cases from Quality Cartridges, stamped .425 Fossdal.
The will be 65,5 mm long, or 2.58".
As soon as they are in hand, I will run them through a 10,75x68 FL-die, insert a bullet, measure and order reamer. The reamer I first ordered I canseled, as I wanted the presice measurments on the brass to use before ordering a reamer.

The cartridge is designed with a ghost shoulder and a parallell neck, like the .470 Capstick, to improove bullet hold and taper. It will also only rquire a two-die set.
Link to drawings at ammoguide: http://ammoguide.com/?catid=601

So there.
No more changes, just wating for parts.

My sincere thanks to the good man Boomstick for helpful input, donation of .240 Wea'by brass and his genuine interest!
Also thanks to ramrod340 for helpful brainstorming, it was fun!

Bent,
I have followed this closely from the begining. What a awesome idea come to fruitition! Once I get my 500ar and 6mmbr tube gun built its on to this one. I love it. 5 down!!! Please keep us updated.

quote:

Also thanks to ramrod340 for helpful brainstorming, it was fun!

I enjoyed it. It is looking good. Going to leave my little 411 in the dust.

Glad things are comming together!

This is one of the best ideas here on AR

Anyone going to have a 240 WBY and 425 Fossdal switch barrel?

Those 350's should be good for up to the big 5!

Hey Bent...

This deserves to be on the big bore board now...

Just like the 470 Mbogo it is now a proprietary cart with headstamped brass made by Qual Cart!

quote:

Anyone going to have a 240 WBY and 425 Fossdal switch barrel?

Wow! What a great idea! I hadn't even thought of that yet. 26" tube on the 240 and a 20" on the 425.

Its a one gun safari...

Thanks guys!

And remember, any cartridge made on the .30-06 case can be used in a switc barrel rig!

Boom, I'll wait to take it to the BigBore forum until I have fired it! You know how they are, since I presetly don't own a bigbore, they probably will tell me it can not be done, and that I have no buisness doing it!

Any thoughts as to whether or not the 425 will function in a push feed M700 long action or do you figure this a controlled feed sort of round?

I dont know any reason that it would not work on a pushfeed...

If it is on a long action m700 than you can load out for more room for lower preasure or higher velocity.

quote:

Any thoughts as to whether or not the 425 will function in a push feed M700 long action or do you figure this a controlled feed sort of round

Should work fine. Look at the number of push feed 458s around. This one is same shape just a touch smaller dia.

So the barrel is home, a 24" CM tube from Walther, 0.718" at the muzzle.
The cases should be due in the end of august.
I am just pissed now I did not stamp them .42-.240. "fourty-two-two-fourty". Naming cartridges is tricky buisness.

Oh, well.

Great work Bent
If i were to build one, it would be light and trim, like a 10,75x68 model A ...

Bent,
Just read the post, so I haven't being paying attention. I'm wary whether the 2 die set will work for the straight case ... my CH/4D dies for the 470Capstick are 2 piece and they don't work well at all. The issue revolving around the decapper ball which is too big. I was offered a replacement 3 die set, but figured a way around my problems thanks to a Lee Universal decapper, die with decapper removed and then a case flaring tool.
Cheers...
Con

Thanks for input, Con, I'll keep it in mind! I will oreder a two die-set and look out for the expander button, should be easy to reduce if to big...

No worries mate. From memory the CH/4D was 0.475" which meant as it went down the case it was interupted by the case walls tapering in as the brass got thicker, so it "bottomed out" with about 1.0 - 1.5cm to go. Turn it down or pull it out, you just then need to flare the case mouth ever so slightly to seat the projectile smoothly.
Cheers...
Con

My offer is still there Bent if you want to add a 400/375 nitro to go with your 425. My reamer is just sitting here.

quote:

Originally posted by TSJ:
My offer is still there Bent if you want to add a 400/375 nitro to go with your 425. My reamer is just sitting here.

Thank you kindly, TSJ, I'll take you up on that offer if time and urge is right!

quote:

Originally posted by jeffeosso:
Great work Bent
If i were to build one, it would be light and trim, like a 10,75x68 model A ...

Just my thought, Jeffe!

I got a 3 die set for my 400PDK. Sure makes it easier to load the pistol bullets for plinking.

Mail from QC, tooling is in, cases will be done in a couple of weeks! Two months behind, but stil.....

New mail from QC, cases are DONE!! Just the shipping part......
To say I am exited, is a gross understatement.

Great for you Bent!
600 OK
550 Magnum
550 Express
500 Mbogo
500 AccRel
470 Mbogo (granddaddy of lots of them)
470 AccRel
458 AccRel
425 Fossdal
416 AccRel
4 different .395s (no disrespect, i just couldn't keep up with them)
14 different headstampped big bores from AR, in the last couple years

Congrats Bent! I hope pics will follow upon their arrival

Congrats bent! cant wait to see them!

quote:

Originally posted by boom stick:
Congrats bent! cant wait to see them!

I'll try to get some directly to you before shipping, you might get them before me!

quote:

Originally posted by Bent Fossdal:

quote:

Originally posted by boom stick:
Congrats bent! cant wait to see them!

I'll try to get some directly to you before shipping, you might get them before me!

Yupp, Boomie, just got it confirmed from QC, you have cases in the mail! Please post some pics when they show up?

Man if only I had an extra suitable action