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fraserdouble
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Reged: 06/06/06
Posts: 46
Loc: Australia
Cordite equivalent - WARNING re IMR3031
      #128041 - 25/02/09 10:27 PM

There are some really usefull nitro powder equivalents for cordite formulae around, however does any member have similar formula for IMR 4198. They are good for providing approximate loads for old Brit ctgs. As always start at least 10% below and work up.

Other formulae that I am aware of are as follows.
1.10x IMR 3031 = cordite
1.19x RL15 = cordite
1.31x IMR 4831 = cordite
40-44% IMR 4198 = black powder

Based on the relative burning rates I would imagine that 4198 is close to 1.
Does anyone have better data than this guess?
Fraser


(Added a comment regarding a warning re using IMR3031)

Edited by NitroX (29/06/10 08:54 PM)


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doubleriflenut
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Reged: 27/11/08
Posts: 106
Loc: Chile
Re: Cordite equivalent [Re: fraserdouble]
      #128059 - 26/02/09 02:53 AM

You are right on in regards to the RL15! I have used this conversion in many different doubles and always had great results in accuracy and velocity. I have not used the other formulas as the RL15 is so good, I figured why bother!

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grandveneur
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Reged: 21/09/08
Posts: 1296
Loc: France / Germany
Re: Cordite equivalent [Re: fraserdouble]
      #128060 - 26/02/09 03:11 AM

For reloading Berdan brass caliber 577NE, i use TU3000, about similar to IMR3031, same load that the original cordite load, 90gr.powder and 750gr.FMJ bullet, and i use a 0.5" wad! I had a bad experience by the ignition of R15 in Berdan cases. I think in Boxer cases, no problem. But carefull, we do that under our responsability!

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Marrakai
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Reged: 09/01/03
Posts: 3482
Loc: Darwin, Top End of Australia
Re: Cordite equivalent [Re: grandveneur]
      #128164 - 26/02/09 10:45 PM

Just remember, guys, IMR3031 has been a bit suspect over the years for producing pressure hikes in nitro-express cartridges. Back when that was all there was, it was used extensively, but there are much better powders around these days and its use in NE-equivalent loading should probably be discouraged.

Heresay only, I have never used it personally, but through a gunsmith mate, Vic P_, I know of several nice doubles taken off the face by use of that powder.

Another point to remember is that cordite was OK a hundred years ago when it was the only game in town, but today we can use considerably slower powders for better ballistics, or the same ballistics at much lower pressure.

Remember too that Reloader powders in full nitro loads need wads or filler, a two-edged sword if ever there was one.....

--------------------
Marrakai
When the bull drops, the bullshit stops!
--------------------------------
www.marrakai-adventure.com.au


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grandveneur
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Reged: 21/09/08
Posts: 1296
Loc: France / Germany
Re: Cordite equivalent [Re: Marrakai]
      #163005 - 29/06/10 06:17 PM

Now i reload 600NE cartridges with 100grs of TU3000 powder and a 0.5" wad behind a 900grs FMJ bullet from Woodleigh . The question is the same, why not fast burning powder like IMR3031 for reloading old DR cartridges ? All this old rifles are regulated for cordite, a very fast burning powder with high pressure peaks !

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Ron_Vella
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Reged: 29/04/05
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Loc: Oshawa, Ontario, Canada
Re: Cordite equivalent [Re: grandveneur]
      #163010 - 29/06/10 08:47 PM

Tony,
An acquaintance of mine lost his left thumb and damaged three fingers, about six weeks ago while shooting at a local club. The rifle was a J. Manton, Calcutta, .360 #2 NE, with Jones underlever. The left barrel burst at the breech face and peeled up and forwards for about 10 inches. He was shooting handloads using IMR 3031.Whether it was an overload or one of the mysterious "detonations" we will never know, because: The local constabulary, geniuses that they are, were unable to determine if the right-hand barrel had been fired. So they called their bomb squad who took the remains out into a field and blew them to smithereens with an explosive charge!

Best,
Ron.

Edited by Ron_Vella (30/06/10 12:04 AM)


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NitroXAdministrator
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Reged: 25/12/02
Posts: 39245
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Re: Cordite equivalent - WARNING re IMR3031 [Re: Ron_Vella]
      #163012 - 29/06/10 08:55 PM

Added a comment regarding a warning re using IMR3031

Readers - use at your risk

--------------------
John aka NitroX

...
Govt get out of our lives NOW!
"I love the smell of cordite in the morning."
"A Sharp spear needs no polish"


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beleg2
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Reged: 15/08/07
Posts: 591
Loc: Bahía Blanca - Argentina
Re: Cordite equivalent [Re: Ron_Vella]
      #163013 - 29/06/10 08:59 PM

Ron,
Sorry to hear of his accident!
Hope he is recovering well.
I losted my right thump many years ago too.
If i can help him in any way please let me know.
Martin

BTW: it looks very dangerous to use 3031.

Edited by beleg2 (29/06/10 09:00 PM)


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bonanza
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Reged: 17/05/04
Posts: 2335
Loc: South Carolina
Re: Cordite equivalent [Re: Marrakai]
      #163015 - 29/06/10 09:35 PM

The double edge sword to me is the profile of old double rifles. You can't use slow powder because the tubes are so thin starting from the fore stock. Fast powder can spike.

Varget and R15 are medium powders that are probably the safest.

Modern barrels are made from Chrome Molybdenum steel that is very strong and highly elastic.

But, here is the reality. Every time a rifle is shot the barrel is strained which work hardens it. The metal fatigue, which is cumulative, reaches a point where it can not contain the pressure and ruptures.

With modern 4130/4140 that's thousands of rounds, with the old low carbon steel, who knows?

--------------------


"Speak Precisely" G. Gordon Liddy.

"Life is absurd, chaotic and we must define its purpose with our actions" Abert Camus

"I''m the dude playing a dude disguised as another dude."

"Yo! Mr. White"


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DarylS
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Reged: 10/08/05
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Re: Cordite equivalent [Re: bonanza]
      #163024 - 30/06/10 12:45 AM

Modern powders lack the low density (bulk) of the old ones, meaning they don't take up enough case space when loaded at maximum pressures and therefore need a filler of some sort - or the use of a powder that ignites readily, not needing a filler.

For me, IMR 3031 is too fast burning for large cases and becomes somewhat erratic in them at higher pressures.

The only powder I can think of that you can possibly get away with no wad, is H4895, yet it-too works best with a wad of some sort.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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grandveneur
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Reged: 21/09/08
Posts: 1296
Loc: France / Germany
Re: Cordite equivalent [Re: DarylS]
      #163079 - 30/06/10 06:40 PM

The risk of reloading big bore cartridges is in all cases, without a test barrel, very high ! Varget is a fast burning powder in the class of IMR3031, TU3000 or R902/R903. All this powders are recommended and in our countries the first choice for reloading cartridges like the 360NE or the 9,3x74R ! With low burning powders i had a lot of ignition problems with hanging fire and in many cases a bullet fixed in the barrel after only ignition of the primer ! Not very safe too ! THE PROBLEM ARE THE OLD RIFLES THAT WE USE ! Better we dont reload this big old cartridges and use factory loads ! I shot a lot of factory cartrdiges caliber 577NE from WR and a few caliber 600NE from Kynoch . Recoil is very stiff, what they put inside ? Are this maximum pressure factory loads safer in old rifles ? I dont know !

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mauserand9mm
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Reged: 03/09/09
Posts: 1001
Loc: Queensland, Australia
Re: Cordite equivalent [Re: grandveneur]
      #163151 - 01/07/10 10:22 AM

The empty space in the case adds to the pressure spike problem. In Graeme Wright's book "Shooting the British Double Rifle" he includes reference to some testing done many years ago where a tube was filled with a small amount of powder and the location/disbursion was varied. Pressure was monitored at different places along the barrel. If the powder was spread uniformly along the tube (even though there was still a large air space) the pressure was uniform throughout the tube If the powder was placed at either end, the pressure spiked at both ends while the pressure was normal in the middle.

Cordite was produced in long strands that went from case end to projectile underside, so a reduced charge didn't appear to suffer the pressure spikes.

Graeme's book includes the effects of different types of fillers and powders etc. I can't say too much without risking copyright issues. And I'm not getting a commission from Graeme for mentioning his book either.

Long throats exacerbate the ignition issues. I've had lots of drama getting reduced loads with cast projectiles to light up reliably in my 458WM (it's a CZ550 magnum). I've managed to get a few projectiles stuck in the barrel on different occassions.

Always be sceptical of any load advice or recommendations given. Publications would be more reliable source and even contacting the powder companies is worth a go.


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grandveneur
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Reged: 21/09/08
Posts: 1296
Loc: France / Germany
Re: Cordite equivalent [Re: mauserand9mm]
      #163169 - 01/07/10 03:23 PM

Today i use wad's in all cases and for both powders that i use, TU3000 or IMR4831 . I have the second edition of graeme wright book's since few weeks. This book is the experience of the autor ! But i miss a lot, for exemple he dont consider the warming up effect of DR barrels during the shooting !

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