I'm trying to get an understanding of what this cartridge would look like
up close; it's not entered in www.ammoguide.com - maybe one of you who
has the know how would do that? Also, can some one explain the "ghost
shoulder" feature? Would this design using a rimmed piece of brass, be the
IDEAL way to design a cartridge specifically intended for a falling block
actioned rifle? Thanks friends

I can send photo of brass after sizing that shows the shoulder. My understanding was to give the last 400/1000 straight side to use 2 reloading die and more uniform tension?

basically, when you have a very little taper case, you have a section that is parallel, rather than tapered -- the 495 is an interesting caliber, btw -- however, not bragging on this, my 500 AccRel is a better design, so is RIP's 495..

on shoulder, it can act as a venturi, as we have proved with the 458 AccRel - its 2% larger than the 458 lott, but the shoulder is a mechanical advantage and gives substantially better than the 1/4 of volume gain to velocity, due to change in case design .. this has been proven on 5 continents, btw

technically, one has to pay Art a royalty on his copyrighted cases and dies -- mine are copyleft and open for use

Both answers are appreciated very much! I'd enjoy seeing a picture posted. May I suggest
www.imgur.com for posting pictures. No join-up is required, but I've found it so easy to use
this site THAT I DID JOIN. [ FREE by the way]

Jeffe, Please explain the Venturi benefit. I'm asking about number of times brass can be
reloaded as part of the analysis of which cartridge design to pick, as well keeping in mind
that in a falling block with a rimmed cart. the headspacing will be done on the rim, not
on a shoulder of any sort, Correct ?

the 495 a2 is a belted, not rimmed cart, btw - it's a worked over 460 weatherby, necked to .510, operating at likely 60K psi -- sorry, that may not have been clear.

quote:

Originally posted by D R Hunter:
Jeffe, Please explain the Venturi benefit.

i can try, but i think that
the wiki link boomie posted does a better job ..

quote:

Originally posted by D R Hunter:
I'm asking about number of times brass can be
reloaded as part of the analysis of which cartridge design to pick,

this is more a function of pressure and working-the-brass, in that it matters a lot of how much the brass is resized, in terms of movement, not count. for a DGR, one should full length resize to ensure fit and function, though neck or partial resizing will reduce the "work" on the brass

quote:

Originally posted by D R Hunter:
as well keeping in mind
that in a falling block with a rimmed cart.

this may limit your upper working pressure, but a 577/500 with a .510 bullet would be great, though no real improvement of a 500 NE

quote:

Originally posted by D R Hunter:
the headspacing will be done on the rim, not
on a shoulder of any sort, Correct ?

ahh, well, now, that part depends, as the datum (headspace line) can be case mouth, shoulder, belt, or rim -- in fact, the same cart can be done different ways, take for example, the belts mags - many people prefer to headspace off the shoulder on the smaller ones, rather than the belt, claiming it leads to better accuracy ..

if you need a rimmed cart, i would offer that the 45/120 is the cheapest possible full power big bore in a falling block, if you want a .510 bullet, i would certainly offer the 500 NE, though there are some others that can be more interesting --

Thank you both for all the info. I'm actually interested in
creating a modern design and manufacture, true .400"
diameter bullet, based cartridge, that would be rimmed, in-
tended for a Ruger #1 rifle action and any very similar action.



_________________________________________
G S CUSTOM EXPANDING HUNTING BULLET

RIP is closer to that end of the "forties" space than I am --

if you are wanting to do your own, soup to nuts, i would suggest the 500/416, necks to .400, and go from there -- modern brass and reloading data.

in fact, it would be a fairly easy wildcat to do, from a working prospective, as you should be able to easily duplicate the 500/416, and since in a strong action, you aren't as limited as if building in a double rifle.

then again, a 45/120 necked down would also work, and the brass would be, in comparison, much less expensive. would result in a "more" unique round --- though the 450/400 would be a close comparison in terms of case capacity and results


heck, let me try, just once, to talk you into 450/400 NE - this is an entirely known path

soooooo you could buy a 405 win or 450/400 Ruger #1 and do a two turn paper patch and shoot a true .400" bullet out of a .410" barrel. If that is not a crank turner then may I suggest the 40BSA that is a rare .400" bullet IIRC or a 400-375 Flanged wildcat.

I don't know how I found it years ago, but Municion.org is a wealth of information. You just have to use google translate and do a bit of math.

495 A²

I guess you could use 500SW bullets for plinkers?
500SW T-Rex Bullets

Good Luck!

Thanks very much guys. I guess I just want to "create" something!
How about .400" diameter bullet fired from 9.3x74R brass using
a Ghost Shoulder. Why would going with a typical shoulder like the
450/400 Jeffery has be better?

Bullet weight, say 380 grains, MV say 2400 FPS. Call this a compet-
itor to the 500/416 for falling block actioned rifles. Where am I going
wrong?

I can see pistol bullets making the .400" rifle round quite interesting for plinking, small game and cost reduction. If you wanted a bolt action .400" wildcat, a simple neck up of the 9,3x62 could be an interesting wildcat. A metric version of the 400 Whelen as it were. 10x62

quote:

Originally posted by D R Hunter:
Thank you both for all the info. I'm actually interested in
creating a modern design and manufacture, true .400"
diameter bullet, based cartridge, that would be rimmed, in-
tended for a Ruger #1 rifle action and any very similar action.

Ed Wolsum did that about 15 years ago.
.400 Tembo of true .400-caliber, Barnes Bullets custom ordered.
IIRC, he had both a rimless for bolt-action rifles and a rimmed version for double rifles.
But it has died on the vine.
Just like my .395-caliber wildcats, for which I had Harry McGowen make barrels and GSC made bullets.
I used the 9.3x74R brass for a .395/400 NE 3" Aboriginal cartridge, aka the 10.03x75R, in a Ruger No.1 single shot.
Max did one too.
And a .395/.375 Ruger Max, aka .395 Max.
Max and a buddy of his did one of those too.
Then there is the .395/.416 Rigby aka .395 Tatanka.
And the .395/.338 Lapua Magnum, aka 398 Lapua Magnum.
And the .395/.375 H&H Magnum, aka .395 H&H.

Be careful, this way lies madness ...

And the ghost shoulder is nothing of significance.
Sure sounds neat though.


Anyone who claims the .458 Winchester Magnum is ineffective has either not tried one, or is suffering from .458 Winchester Magnum Derangement Syndrome.
Rip...

Thnx RIP

http://www.municion.org/400/400Tembo.htm

Go with the 450-400 necked down to .416. Due to lack of components in the 1950s I built a double rifle in that caliber...I still have a set of new RCBS custom dies that I would sell for half price!!

It would be a great caliber for a single shot, and penetration ala SD is better than the 450/400s .423 bullet gr. for gr.

I shot GS Custom bullets in that rifle some years later, The flat nose solids and the North Fork cup points are awesome killers of big stuff.

quote:

Originally posted by Atkinson:
Go with the 450-400 necked down to .416. Due to lack of components in the 1950s I built a double rifle in that caliber...I still have a set of new RCBS custom dies that I would sell for half price!!

It would be a great caliber for a single shot, and penetration ala SD is better than the 450/400s .423 bullet gr. for gr.

I shot GS Custom bullets in that rifle some years later, The flat nose solids and the North Fork cup points are awesome killers of big stuff.

Ray,

I think you have some typographical errors in the above.

- "450-400 necked DOWN to .416"
450-400 flanged brass, either 3 in. or 3.25 inch, usual bullet diameter is .410" or .411"

- "SD is better than the 450/400s .423 bullet"
.423" diameter is the 404 Jeffery bullet, (slightly rebated rim on that brass, definitely NOT rimmed)

if you want to do this as a wildcat, and not a 500/416, i wouldn't recommend starting with high dollar brass --

the 45/120 NORMA brass is outstanding, cheap (when compared to anything that says NE on it) and rimmed.

necking it to 416 is a trivial issue, in reloading terms -- and the resulting case would be within 2% of a 450/400 necked down

but i've said all this before, so i guess i'll shut up on the matter

quote:

Originally posted by jeffeosso:

heck, let me try, just once, to talk you into 450/400 NE - this is an entirely known path

I have decided that JEFFEOSSO has done me a huge service with the above bold words.
Though I reload, Hornady does loaded ammo in this caliber for Pete's sake...
Here It Is / And Here