Anybody know what the CUP or PSI pressure is on this. Not hotroded stuff, just factory spec's.
I assume its low pressure, but I looking for the facts not the assumption.

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Thanks Alf,
Exactly what I was looking for.

Governing Body: Commission Internationale Permanente (C.I.P.)

CUP ... maximum average ... 46,444
CUP ... maximum individual ... 53,411

Piezo PSI ... maximum average ... 52,975
Piezo PSI ... maximum individual ... 60,929

This is from the A-Square manual, thanks to Art Alphin, a great book.

Alf is the guru here on this cartridge technical wise. Ray is the Yoda involving use of The Force, for Jeffery Knights.

You see it is supposed to be a low pressure cartridge around 50,000 PSI.

This is in deference to all the old butchered standard M98's on which many of the .404 Jeffery's were built.

In a true Magnum length action (Brevex, CZ550, BBK, Dakota, Prechtl, etc.) or a Winchester M70 Classic, it becomes a 60,000 psi cartridge like all the modern ones.

With modern powders like H4350 Extreme or H4831SC Extreme, one can stay down around 2125 fps (original factory specs when Yoda was in diapers) with 400 grainers and only be at double rifle pressures, under 40,000 PSI.

I hate CUP values, and wish someone would ban their use and require all reporting in PSI. PSI numbers are absolute values that are comparable between cartridges. CUP numbers are unique to a specific cartridge and not comparable between cartridges.

quote:

This is in deference to all the old butchered standard M98's on which many of the .404 Jeffery's were built.

Rip,

Exactly my reason for asking, I am like a dog with a bone on a 404 using a FN action. These numbers help.

As RIP says, I ONLY deal in the hot rodded varity...none of that Mickey Mouse stuff for this kid.

Neva, I say neva, send a boy to do a mans job!

quote:

Neva, I say neva, send a boy to do a mans job!

I'd say a 404 at 60,000 PSI is living up to that statement.....

That's one helluva charge!!!!!

Don't know, I never that far with mine...I use IMR-4831 and its pretty hard to get hot pressure with it as case volume won't hold enough to get totally out of hand...Not so with most other powders...

but like the 30-06 and .270 its the best powder for velocity by far...Northfork did a lot of testing ref. my loads and results were very good with my top load but he got less velocity than I by about a 100 FPS..and at reasonalbe pressure.

What exactly is the case volume on these?
Is there any difference between Kynoch and Norma?

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RWS made the best 404 brass with the highest case volume as I recall..I stil have a reserve of that good brass somewhere in my shop...

quote:

Originally posted by Atkinson:


Neva, I say neva, send a boy to do a mans job!

and if one does send a boy yo do a man's job, nevea complain about his methods!!

jeffe

Ray, where is that RWS 404 Jeffery brass you promised me after our last gun deal?????

Now Ray, weren't you getting 2650 with a 400 gr bullet? Now surely you aren't going to tell me that it is at 50,000psi and still getting those 416 weatherby velocities. Or perhaps I misremember what velocity you were getting!?!?