I'm reading "Hell, I Was There" by Elmer Keith, published 1979. He clearly says he DID NOT mix powders to form the Duplex load, rather, he and Charley O'Neil developed a front ignition cartridge. He let the mis information about mixing using powders of different burning rates published by the America Rifleman stand because he didn't want the German technitions to understand what he had done.
FYI, the tube for front ignition was about half the length of the cartridge, apparently filled with black powder and sealed with a dab of wax at the end.
His claims for this method of ignition were an absence of muzzle flash, longer barrel time curve, reduced pressures, higher velocities and uniform velocities.
So, who mixes powders and why?

quote:

Originally posted by I Bin Therbefor:
So, who mixes powders and why?

Who? Foolish reloaders.

Why? Because they think they are smarter than
the chemical engineers and ballisticians
employed by the powder manufacturers.

first, I strongly suggest NOT mixing powders.. it's dangerous idea

i think your supposition is wrong. Ackley clearly remonstrates kieth's loads.. and freely used duplex and triplex loads.

the extended primer tube as a different developement... this was a take off of the artillery rounds. not many were made and NONE in 44 special

get ackley's books,.. there's a poster or two on here that has incredibly specific knowledge of this exact area...

jeffe

I am trying to remember from 1971 but before
the 454 ammo was produced by anyone I read the reload data in a gun mag and it was a triplex load. I will look as i think i still have it.
Gene
NO i never tried it or know anyone that did.

quote:

Originally posted by craigster:

quote:

Originally posted by I Bin Therbefor:
So, who mixes powders and why?

Who? Foolish reloaders.Yes! In my case this was true

Why? Because they think they are smarter than
the chemical engineers and ballisticians
employed by the powder manufacturers.This, however was not the reason

You get this jug of 5020 and right away you wonder, what am I going to do with this?

By the time you've duplexed to the point you get all that stuff to burn *** you find you got too much of it in the case. Sadly I did it more than once. roger

OK, I'll admit it. I did it myself a couple of times. 7 grains of 2400 under 55 grains of FFg black in a 43 Mauser and something close in a 43 Spanish. Worked just fine, almost zero fouling compared to straight black.

The factories (especially Hornady[light magnum?]) do use mixed powders to boost, but they employ pros, have tons of insurance, and mixe in huge quantaties. These avoid variables, such as one small batch being faster than the next (home based reloader). As for "powder stacking", don't do it unless you know how to regenerate limbs.

Factories do not mix powders, they blend different batches of a particular powder to acheive the sought after burn rate and characteristics. That's why 4831 that you buy today is relatively close to the 4831 that you may have bought two or ten years ago. Duplex loads are a completly different thing altogether. There, two or more powders with different burning rates are "stacked" in the case and kept separated by filling the case so that the powder column is compressed. In theory this keeps the different powders seperate but in practice it didn't always work. Keep in mind that when Keith, O'Neil and others experimented with this idea there weren't a lot of different powders available to them. The slowest burning canister powder was IMR 4320 or, later, IMR 4350. With all of the powders available to handloaders today there isn't much use for duplex loads in small arms applications.

Ray

quote:

Originally posted by craigster:
OK, I'll admit it. I did it myself a couple of times. 7 grains of 2400 under 55 grains of FFg black in a 43 Mauser and something close in a 43 Spanish. Worked just fine, almost zero fouling compared to straight black.

I use to do the same thing with cannons I built
a few moons ago. sure was easier cleaning. roger

I think we're talking about two very different techniques. A duplex load is a small charge of one powder (usually very fast like Bullseye) on the primer topped with a larger charge of much slower powder. Or like some already said, a small charge of smokeless under black powder for even pressure and less fouling. They are not "mixed" but stacked.

If Keith filled the tube with black powder and loaded some other smokeless in the case then that is by definition a "duplex" load because it uses two different powders.

Dick Casull was one of the more well known proponents of duplex loads and achieved some amazing results with the 45 Long Colt way before he came up with the 454 Casull but I think it would be foolish for me or any other average Joe to try to copy his results without some experienced assistance.

As far as "mixing" powders, run for the hills!!

In my book on Gibbs cartridges by Roger Stowers, there is a section that was copied from some articles by Rocky Gibbs himself. It talked of front ignition and duplex loading. The primer tubes installed in the case ignited the front of the powder column and kept the burning powder inside the case instead of the barrel. In the duplex loading he ignited a slower burning powder to gently accelerate the bullet out of the case. Then the faster burning powder at the bottom of the case was consumed and gave the bullet the extra "push". His theory was there was less erosion because the burning powder was contained in the case, plus higher velocities were attained due to using a partial load of faster burning powder. There are quite a few loads listed in the book along with how to install the brass tube in the cartridge case. (These were all compressed loads that held the powder in place.)

It's all pretty interesting reading. While I don't mind fireforming cases and all the extra work involved with owning a "wildcat" cartridge, I'm not quite ready to start drilling out primer pockets, installing brass flash tubes and experimenting with multiple powders IN THE SAME CASE!

Unfortunately, most of the claims made by shooters experimenting with flash tubes and/or duplex loads are not substantiated and are probably exaggerated. There weren't a lot of chronographs available in those days and pressure testing equipment was available only in the factories. One interesting fact about flash tubes is that they filled a goodly portion of the powder space and loads had to be reduced accordingly. In order to bring case capacity back up it was necessary to go to a bigger case which would have been a better idea in the first place. But, as a wildcatter and experimenter myself, I can understand what drove those guys to their experiments.

Ray

Reread Keith's writings. He DID use duplex loads, fast powder under a slower powder. Think about it, back then there were few powders to play w/ so if you want a something slower than 4895 but faster than 4350, you had to mix.
Reloaders in other countries that are limited to powders also do this (RSA comes to mind). They actually mix two powders together by weight. I have a friend there that does this. We are lucky, we have access to the worlds powders & have no need to "invent" a powder, just buy what you want.

By the by, in his writings, Keith uses duplex to mean two shells. He counts the tube which carries the primer flash towards the front of the cartridge as one shell. that way of ignition is duplex, two shells.

quote:

Originally posted by I Bin Therbefor:
By the by, in his writings, Keith uses duplex to mean two shells. He counts the tube which carries the primer flash towards the front of the cartridge as one shell. that way of ignition is duplex, two shells.

\

I am sorry to say that you are incorrect. Duplex means TWO powders. The end.

what you are now calling "two shells" is actually a multi-projectile load.. which keith didn't, as far as I know, work with outside ratshot in the 44.

He doesn't count the "front burning primer" as a shell... nor a load... these are MIXED data contents... extend primer tubes and all parameters around them are A thing... fast and slow powder in the same case are ANOTHER.. and the name for that "another" is duplex.

jeffe

I'm afraid you're going to have to take this one up with Elmer. My reference is from the book I quoted above. I've returned it to the local library so I can't give you the specific page numbers. None the less, he clearly states what he means by duplex and that he let the notion that he was mixing powders stand until after WWII for fear the Germans would catch on to front ignition. He also mentions people blowing up guns by mixing powders to duplicate his results. He published the results but not how he accomplished them much earlier than the end of the war.

Dunno if Keith did or didn't, but Mr. Casull did. So does the Lyman manual, listing duplex smokeless and black loads for most of the large volume BP cartridges. Primarily used to reduce fouling there. I've also read that the rounds fired in the Abrams tank are triplex loads FWIW.

respectfully, i disagree.

please go find the book and give me the ISBN, i'll read it myself.

Till then you are 1 in quite a few that calls "duplex" something other than DUPLEX LOADS

like calling a torque wrench a monkey wrench... yeah, they are both wrenchs, and that's where it ends
jeffe

Reasonable request
Hell, I Was There
Paperback: 308 pages
Publisher: Blacksmith Corp (November, 1989)
Language: English
ISBN: 0941540162
Look at the section titled "Birth of the Duplex". The copy I saw was a library hardback so the page numbers won't match this softback edition, but should you find the hard back, the section starts on pg 177.

I guess I've been pretty lucky for 40 yr. We've blended milsurp powders to get a desired burn rate. The ones we use are not real different in burn rate. We start with H870 and then try to speed it up to get desired results for a specific case,blending a faster ball powder. A chronograph and micrometer tells one how you're doing.
I also use the duplex idea for my 35-404imp and 35-416Rigby. The latter is new and I haven't got too far with it. I've tried 700x under wc867.
FWIW the closest I've come to limb loss was when I mistook imr4198 for imr4895.Was in a 243 and we had to unscrew the barrel to open the bolt.The chamber was bulged but there was no lug setback.
While I agree these practices are dangerous,it can be done safely with the use of proper equip. and some common sense.
When we started this there was not a great selection of powders for overbore cart.

That it one gauges them that Elmer Keith conceived. Could you tell me the nomination is the casing which it took to make these gauge is measurements of the Merci casing

I still can't locate original material but following the "he's reported to have" type of articles what appears to have happened is:
* Keith observed that a lot of powder was being burned in the barrel rather than the shell.
*The "O'Neil" of the team evolved a method of front ignition that was designed to start the powder buring at the base of the bullet and then down into the shell.
* Either later or as part of this process, Keith or O decided to try and maintain an even pressure on the bullet as it traveled down the barrel by LAYERING (not mixing) powders with two and then three different burning rates. Again with front ignition.
* Keith is claimed to have maintained a lot of improvenet in velocity, consistant velocity from shell to shell and a reduction in recoil from this technique.
* Some folks not understanding what Keith was doing tried to replicate what the rumors said he was doing and MIXED the powders with drastic results, none of them good. The powders being mixed had drastically different burning rates.
* The late Gibbs appears to have taken up the front ignition work without the layering of powders. In the 10th Edition of Cartridges of the World, Stan Skinner reports some experiments with front ignition of his own. He reports that he could not find the resutls of Keith's experiments but did find the results of Gibbs' experiments.
* Skinner reports that with front ignition the powder does burn within the shell. From this he concludes that better barrel life would result. In adition he reprots remarkably little variation in velocity between rounds but he points out that he fired a too few rounds for a true experimental sample.
*Keith also claimed that when loaded to the brim the layered powders DID NOT mix even when the shells were subject to vibration.
That's where I am at present.
My interest is in the improved barrel life, improved accuracy and "reduced recoil" (claimed by Keith).

Ok Cheech,
I live in Canada, where a few years ago we could not get our Hornady ammo across the line (I worked for a gun shop). The reason was Hornady would not disclose the powders MIXED in the light magnum loads to our customs. When we called our Hornady rep. he gave uas the same answer, that they mix powders in large batches to gain signifigant increases in velocity with lower pressures. Now why would a factory blend different lots of the same powders when the manufacturer has already done so to maintain accurate burn rates? Because the facts have shown (as most professionals will tell you)that burn rates have fluctuated enough over time that your standby load 10 years ago could lock your bolt up with a new lot of powder Your response seemed a little ignorant and I think I smell a armchair quarterback. Keep spouting unsubstantiated absolutes (if you need this translated, ask your handler), it only makes everyone else seem smarter.

Jeffe, looks like he was right, I pulled it off the shelf and took a look, Keith did use the term incorrectly. But then again, he thought the Germans would pick up on something "new" if he clarified it and therefor let people get hurt for being stupid enough to try what the magazine published.

Fleming, took that a bit personal didn't you? wrong or right I don't think cheech was trying to piss in your cheerios.

Whether factories or people mix powders the only way to know what affect it would have on barrel life would be to do a true test, barrels from the same batch of steel on identical rifles, same brass and primers and then get loads that have same ballistics with the different loading methods and fire the barrels until both show erosion, count the number of rounds.

Cheech has something, most people, especially in the past, didn't have the equipment to really back up their experiments and load development with emperical data. Just like lots of guys now load to the book and then think they are automatically getting what the books says.

Bin, no offense meant but you are wasting your time if this is just to extend barrel life. Weight out the POSSIBLE (and not supported by data remember) benefit of having front/middle/diagonal ignited charges in the cartridges, layering powders etc. VS. modern primers, powders, knowledge about gun maintenance and danger of overloading. Barrels will last longer than people think and the time you would spend doing all this other will quickly outstrip the cost of having the gun rebarreled after a few thousand rounds.

Unless the gun is badly overbore you should get a lot of time out of it. I know somebody who shot the barrel out of an 06, it was a springfield he got when he was about 15 or so and he figures he put around 10,000 rounds through that barrel (still has the rifle but now I think it is a 257 Roberts). And guys with 220 swifts get about 2k rounds through them don't they? Not shabby considering what it is doing.

Red

Dago Red; thanks for the confirmation. Your point on barrel life is well taken. The bottom line is that I'm a "tinkerer" and am trying to see if there's enough to front ignition to try some experiments.

By the way, try this site

http://www.frontierbullets.co.za/hunting.htm

and click on the 458 Express picture. The claim is that the developer of the cartridge tried some experiments with duplex loading, using SA powders, and got a reduction in chamber pressure of 13,000 psi with equal performance. Facinating but not for me. I'll stick with front ignition experiments for now.