bigokie
.224 member
Reged: 24/04/04
Posts: 4
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I know this has been brought up quite a bit lately. But I'm wondering on making a double over/under out of a Ruger Red Label. I've seen some posts where this was done. Has anyone done this? Can anyone give me details on this. I have the book on making a double out of a shotgun, it should be here shortly. I'm thinking of making it a 450/400, 450 or a 470. Any ideas on this?? Would there be a better action for this? I'm also looking for a greener or browning bss, so if I find one of those first I'll do that. Thanks in advance for any help, Matt Sheik
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bigokie
.224 member
Reged: 24/04/04
Posts: 4
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Okay, found some older info on this. Now I need different info.
Can anyone give me pressures of the following, 300 HH mag, 450/400, 450, 470 and 500/465. Any help would be great. Thanks
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Marrakai
.416 member
Reged: 09/01/03
Posts: 3674
Loc: Darwin, Top End of Australia
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From the ballistics chart in the 1926 ICI catalogue:
.300 H&H Magnum : 18.5 tons
.450/.400 Jeffery : 16 tons
.450/.400 Magnum NE : 16.5 tons
.450 : 17 tons
.470 : 14 tons
.500/.465 : 14 tons
...and although you didn't ask, the reason everyone likes the .450 No.2 for this kind of thing : 13 tons!
Hope this helps.
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Marrakai
When the bull drops, the bullshit stops!
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www.marrakai-adventure.com.au
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DUGABOY1
.400 member
Reged: 02/02/03
Posts: 1340
Loc: TEXAS USA
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David Yale of Yellow Jacket, Colorado, USA builts double rifles in most of the .400, .458, and .470 NE rounds, on the Ruger Red Label! Someone here may have a link to his operation! 
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..........Mac >>>===(x)===>
DUGABOY1, and MacD37 founding member of DRSS www.doublerifleshooterssociety.com
"If I die today, I have had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"
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470Rigby
.333 member
Reged: 23/02/04
Posts: 328
Loc: Melbourne, Australia
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bigokie,
Another consideration in deciding on a suitable action/cartidge combination is cartridge head size, for a variety of reasons, viz;
1/. Firstly, to allow for sufficient chamber wall thickness, a bigger head size will obviously require an action with a standing breech big enough to accommodate the barrels. May be an issue if you are thinking of using a small bore Ruger U/O action.
2/. The bigger the area of the cartridge base, the thrust on the standing breech is proportionately higher. The reason why doubles for smaller high intensity cartridges can be built on lighter frames. Probably the reason why the pressure "king" of British NE's the 450x31/4" which originally went to 17 ton/sq.in was manageable, by virtue of it's comparatively smaller head size.
3/. Although preferable that you do not use an action with disc set strikers, if you do, the base diameter has to be big enough to ensure that it is adequately supported by the standing breech, and not the striker discs.
As for pressure, here are some CIP pressures taken from the 1989 British Rules of Proof. Presumably, these figures reflect what can be achieved with modern loads.They are given in "bars", and expressed as the Highest Mean Service Pressure (Pmax). The Highest Individual Pressure(Pk) is rated 15% above that and the Minimum Proof Pressure(PE), is 30% over Pmax.
300 H&H.....................3700 bar
450/400 NE 3" ............2500 bar
450/400 Mag.NE 31/4"..2600 bar
450 NE 31/4"..............2700 bar
470 NE..................2400 bar
500/465 NE................2200 bar
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atkinson6
.375 member
Reged: 26/01/04
Posts: 678
Loc: Idaho
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David Yale
14386 County Rd U
yellow Jacket, Colorado, 81335
Tel: 970-562-4225
Fax 970-562-4226
Email: smtinc@fone.net
Davids wife Cathy does great work on leather covered recoil pads btw...Tell them hi for me...
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HawaiiPD
.224 member
Reged: 05/05/04
Posts: 14
Loc: Oahu, Hawaii
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A question on proof pressure of a modern gun.
My on the barrel flats of my Wm. Douglass 470 London Proofed
in 1998, is stamped the proof pressure of 3120 BAR and I believe the gun was regulated with Federal ammo. On the top of the barrels is printed " .470 NE 500 grain bullet. What proof pressure is this, Pmax,Pmin, Pave? Is 1 BAR equal to 14.7 psi at sea level? So 3120 x 14.7 psi = 45,864 psi????
In the A-Square reloading manual "Any Shot You Want.", 470
NE is rated with a Piezo psi max ave at 39,187 and
Maximum individual at 45,065. Their recommended loads "red
line" anything over the 39,187 figure.
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470Rigby
.333 member
Reged: 23/02/04
Posts: 328
Loc: Melbourne, Australia
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HawaiiPD
The 3120 BAR stamped on your Wm Douglass is the European Controlling agency CIP's minimum proof pressure, which is 30% over the Highest Mean Service Pressure, that is, the actual pressure developed by CIP approved "factory" loads. This is 2400 BAR for 470 NE, but that is a copper crusher measurement.
Bob Forker in "Ammo and Ballistics" gives the Pressure Tansducer equivalent pressure at 2700 BAR which converts to 39,6790.6 psi, slightly higher than A Squares "red Line".The conversion factor you used is for relating "atmospheres" to psi. The correct factor for BARS to psi is 14.50377; similar, but different!
But, I don't know how this relates to SAAMI pressure tranducer figures.
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4seventy
Sponsor
Reged: 07/05/03
Posts: 2210
Loc: Queensland Australia
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In reply to:
The bigger the area of the cartridge base, the thrust on the standing breech is proportionately higher.
I've seen this written a few times and am wondering where it originated and is it correct?
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470Rigby
.333 member
Reged: 23/02/04
Posts: 328
Loc: Melbourne, Australia
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4seventy
It's just the immutable laws of physics at work! The same reason a Hovercraft can lift huge payloads on just a few pounds of pressure.
For an explanation of how to calculate it, go the Lilja Barrels Website.
Have you noticed that Ruger have started to pour cold water over Winchester's Super Short Magnums because of excessive bolt thrust, by virtue of their wide bases?
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