Fireforming Rebated Cartridges

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longshooter99

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Hopefully this weekend I will become a member of the reloading world, if I make it up to Cabela's on Sunday that is :D Anyways, like most of you guys I spent a good deal of time dreaming up wildcat ideas and dream rifles.

One of the wildcat's i've been thinking about lately would be a a rebated rim cartridge similar to the .284 Winchester. For those of you unfamiliar, the .284 has a standard rim size of .473, but a base diameter of .501 The cartridges I plan to load for at first would be my .270 Win for which I have been saving all my brass for the last year.

I've been thinking of a big bore based on the .270 cartridge. I know of the Whelen family, 35, 375, and I think I remember the 400. The main problem with the 400 Whelen is that there isn't much of a shoulder to head space off of. This is where the rebated rim comes in.

I was thinking of blowing out a .270 casing to the same body diameter as the .284 and then necking it to a .40 cal bullet. My question is, can you blow a casing out that much without stretching the brass too much? The rifle i would use this with would be an old mauser action I have.

Thanks
 
No, you can't!

Don't even think about trying it.

If you want a 'wide body', 'Magnum capacity' case with a standard 30-06 case rim?

There is no way to safely do it without starting out with a wide-body case with a standard rim to start with.

rc
 
I don't want make a claim that I'm a expert at fire forming cartridges. But I would think you are going to have a problem stretching the brass right at the web. When you have excessive head space that is where it separates. That happens with a couple thousandths. Your talking 28 thousandths.
Will sat this its an interesting concept.:cool:
 
Ha I wondered if that would be the case (pun intended). Like I said, i'm pretty new to reloading and have never fireformed anything, so I wasn't sure on what my limitations are. What would you think of using standard .284 cases necked up to .40? I was thinking of .270 casings because I have plenty of them and figured a little more case capacity never hurt.
 
If you really go ahead with this wildcat, buying some .284 brass is going to be chump change compared to the barrel, gunsmithing, and custom dies. Stretching a .284 neck to ..40 might not be possible either. If it is, you'll split the neck first firing. Your bullet choices are very limited as well.

Personally, I'd find a better way to spend my money :)

Laphroaig
 
.308, or .284 necked up?

No again.

It has been tried in the distant past with 30-06 based wildcats.
http://en.wikipedia.org/wiki/.400_Whelen

The problem you will run into is, the same one they ran into.
There is not enough case shoulder left to control the headspace.

You would need to start out with a BIG rebated rim case big enough to leave some shoulder left?
Or, start out with a belted Magnum case that could use the belt to control headspace.

rc
 
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.270 is a good cartridge to learn on. I use 130 grain ballistic tip hornady. They work well with a bunch of powders. Don't try to jump up in velocity too much, that's where the .270 suffers from my experience. Start at min load and work up with 5 shot groups to halfway between min and max. Your sweet spot will likely be in that range as far as accuracy goes.
 
This is why I ask questions, lots of ideas sound great in theory but fall apart when it comes to real world application :p I originally had this idea due to the .458 SOCOM, which has a standard rim size with fat body. I will say that the SOCOM has a base diameter of .541, a full 4 hundredths over the .284, which might be why it works. I thought it would be neat to have that same set up in a longer cartridge since the SOCOM is nearly an inch shorter than the 06 family.
 
And don't start off reloading and try to build a badass new wildcat. There are people who are well educated in the field that do it for a living and anything that we can do they have already done and they did it better. Baby steps keep you from detaching your face from your skull. Slow down and learn the art before you try to reinvent the wheel.
 
.270 is a good cartridge to learn on.
Click to expand...

But, that wasn't the OP's question.

He ask if he could wildcat a bunch of empty .270 brass he has into a .40 cal rifle round.

And the answer is still, NO.

rc
 
The 400 whelen was made from a 30-06 case and the body was .458 necked down to the 405 win bullet which was .411 and the neck was .441. So there was enough shoulder there to withstand a firing pin strike. Griffen & Howe built the rifles and they also loaded the ammo.
I just ran this by a hunting buddy, who remembers the Whelen hay days and he told me that the 40 whelen got a bad rap. Those that had the rifle loved it and they performed flawlessly. All the negative comments came from those nay sayers who never had the gun. Elmer Kieth was a big fan of it.
 
Thanks for your input guys, this is why I come to this site :)

Just to clarify, this is what I was looking for:

1. Can .270 brass be blown out similar to .284? The answer seems to be no, and I was kind of expecting that.

2. (this may qualify as needing a new thread) Can a .284 Winchester, not .270, be necked up to .40? It has a wider base, thus more room in theory to form a shoulder.

3. I don't plan on wildcatting or fireforming for awhile. I shoot the .270 the most and will likely move on to my other milsurps for reloading before I get too crazy (7 and 8mm mausers, .303 British, 7.62x54R) I just have an old mauser action for a project and was trying to think of something unique.
 
#2= Yes.

Next question I would have though is?

Where would you find enough .284 Win brass in this day & age of scarce odd-ball brass to find out?

rc
 
By the time you finished paying for custom dies, getting a custom chamber cut and action work so that it'd feed reliably, you could probably afford a nice CZ in .416 Rigby that'd be a lot more reliable, practical and powerful.

It'd also have the added benefit of not making you worry about erasing your face every time you pulled the trigger.

But if you really want to do this thing, I'd suggest that you start with a .375 Remington Ultra Mag. It has a rebated rim and the case should be plenty strong for such a project, it should be, since it was based on the .300 RUM, which was based on ....the .404 Jeffery!

There's really not a lot new under the sun that SOMEONE hasn't tried at least once
 
toiville2feathers said:
The 400 whelen was made from a 30-06 case and the body was .458 necked down to the 405 win bullet which was .411 and the neck was .441. So there was enough shoulder there to withstand a firing pin strike. Griffen & Howe built the rifles and they also loaded the ammo.
I just ran this by a hunting buddy, who remembers the Whelen hay days and he told me that the 40 whelen got a bad rap. Those that had the rifle loved it and they performed flawlessly. All the negative comments came from those nay sayers who never had the gun. Elmer Kieth was a big fan of it.
Click to expand...
Years ago, I had a rifle built for a friend from a DWM Argentine Mauser in .375 Whelen Improved. Great round, great rifle. Pushed a Barnes 300 gr. at about 2150 fps. Made most from .30-06, some from .35 Whelen commercial cases. The .375 WI case uses a 40 degree shoulder, and there ain't much there. The .400 must be really minimal......
 
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@ StrawHat
Thank you very much for posting that link!
I've wondered over the years why some people loved the .400 Whelen and never had any problems while others cursed it.
It appears that properly cut chambers and dies, along with forming from cylindrical cases, makes this a workable idea.
This old dog has learned a new trick.
 
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