Duplex

[JT-AR-MG42]

Duplexing Black

Oyeboten,

You probably already know duplexing black - 5% - has been done since smokeless has been around. Slight increase in velocity, but the obvious reason is for a cleaner bore between shots. You also end up with less case fouling in the cases of cartridge guns.

Competitions do not allow the duplex loads to level the field. That is not to say that that duplex gives an accuracy advantage at all. They are just cleaner to shoot. One can easily spot duplex by the lack of volume of sparks 'falling' from the barrel upon firing.

Most frontloaders just mix it in prepared charges. With your cartridge gun, try some mixed, smokeless to the rear, and smokeless to the front. I have. Run them over your chrono and you'll see no difference. The primer lights the black first regardless of where the smokeless is. It just makes for a cleaner shooting load. The smokeless is pushing fouling out of the case and bore. Putting it in first is really only a simpler method of controlling consistent powder weights.

Venado mentions triplex. Is that with black? I've never heard of it in blackpowder guns.

A friend and I messed with a Shiloh Sharps .50 and smokeless/smokeless duplex. Fired cases extracted normally and showed no pressure or increased head expansion when measured. We quit because the recoil - more than 45 degrees - was just too much of a fun thing, not because of any concerns over the gun or load.

I do not recommend anything to anybody, JT

 

[Vacek]

Yes, it seems like in the past there was signifigant R&D going on. I read Phil Sharpe's encyclopedic book and reloading was pretty much figured out a generation ago. The tools have gotten more convenient, the components, especially the powder when it comes to temperature seem better, but as they say....Ain't nuttin, new under the sun.

 

[sonier]

Tinkering around the idea of duplex loads sounds fun, but i would first grab a cheap "disposable" rifle such as a old beat up mosin nagant. I would also set up a safe firing range that can be controlled from a distance. Such as a hydraulic trigger or old string trick. Id also want to be hidden from shrapnel so a old concrete bunker, or wall would work. The last thing i would want would have to be a way of testing pressure. Maybe one day here soon i might give duplex loads a try if i save some coin and try a few things.

 

[ranger335v]

"I read Phil Sharpe's encyclopedic book and reloading was pretty much figured out a generation ago. The tools have gotten more convenient, ..."

It was much of the work of that generation that drove the development in reloading tools, components and even our firearms. Many of todays shooters seem to think they invented all the stuff they use and the "old guys" weren't nearly as smart as shooters are now! Huh?

 

[Oyeboten]

Results in both my 'Duplex' Loadings for .38 Special, and, in people's reactions to it even being mentioned at all, both fall upon the exact anticipations I had formed.


Why may this not be a rational matter?

Why insist to interpolate and project into my mention, things I never said, claimed, or had for motive?


The matter seems to invite mostly very messy and emotional reactions, instead of rational interest...

This seems sad to me.


I think the topic itself is in fact more 'dangerous' ( to even mention, let alone, discuss! ) than the actual practice ever was.


Nor is the practice 'dangerous' ( or any more 'dangerous' than using any propellent for that matter ) if rationally thought out, and rationally managed.


Endless examples of doing anything badly or wrongly where bad results follow, can be found for anything and everything in Life.




Impetuousity or transpositions or other errors of technicality or judgement, can or will occasion problems or disappointment in any endevor, and re-Loading is no exception.


I have not recommended anything to anyone about 'Duplex' Loadings, and I have not offered anyone any 'recipes' on or off list.


Sheeeesh!


You need a Snow Shovel here sometimes to clear the BS people can deposit.


Anyway...


Oye...

 

[Oyeboten]

Hi JT-MR-MG42,


You'd mentioned -

Oyeboten,

You probably already know duplexing black - 5% - has been done since smokeless has been around. Slight increase in velocity, but the obvious reason is for a cleaner bore between shots. You also end up with less case fouling in the cases of cartridge guns.

There were and are other reasons, and, other proportions, which at one time were held in favor for Black Powder Rifles, and, for all we know, Pistols also.


Their reason at the time, was for not only a little less fouling, but, for a little more FPS and or for wishing to control the rate of acceleration.

Competitions do not allow the duplex loads to level the field. That is not to say that that duplex gives an accuracy advantage at all. They are just cleaner to shoot. One can easily spot duplex by the lack of volume of sparks 'falling' from the barrel upon firing.

This would depend on the Powder, and the proportion...as for whether anyone would 'see' anything different, or even hear anything different.

Most frontloaders just mix it in prepared charges. With your cartridge gun, try some mixed, smokeless to the rear, and smokeless to the front. I have. Run them over your chrono and you'll see no difference. The primer lights the black first regardless of where the smokeless is. It just makes for a cleaner shooting load. The smokeless is pushing fouling out of the case and bore. Putting it in first is really only a simpler method of controlling consistent powder weights.

I have already done the experiments I had in mind.

But, I may do some more also.

The differences shown with the Chronograph, were in keeping with the anticipations I had outlined in advance...and of course, showed FPS higher than BP alone.

Venado mentions triplex. Is that with black? I've never heard of it in blackpowder guns.

Triplex exists as one more method...and, as with all of this, the powders used, and their proportions and sequence and so on, are important, if not critical.

A friend and I messed with a Shiloh Sharps .50 and smokeless/smokeless duplex. Fired cases extracted normally and showed no pressure or increased head expansion when measured. We quit because the recoil - more than 45 degrees - was just too much of a fun thing, not because of any concerns over the gun or load.

I do not recommend anything to anybody, JT

My only interest so far, has been in loading Black Powder Revolver Cartridges, and, also loading with '777' or other bulky BP stand ins, keeping them in what I believe are conservative pressures, and, seeing what variations on that theme I could explore.

Although I did also take a little deteur to load some Smokeless .45 Colt Cartridges, with 'Unique', and found satisfaction and fun with that.


Black Powder Revolver Cartridges or so called BP '
substitutes' are what I am interested in primarily for now.

And, 'Duplex' variations on the theme, with BP, have been interesting to experiment with.

I kept my experiments conservative, and careful, and I had no disappointment or regret.


However, especially in the absense of details or ways of verifying pressures realized in anyone's particular conditions, I am certainly not recommending or hinting as if recommending, that anyone jump into attempting any kind of 'Duplex' Loadings of any sort.

This is an area where there is close to no published data, and since there are many ways to do it, there are also many ways to make an error of judgement which could result in a ruptured or even catastrophically exploded Gun, and possible injury to the Shooter or to bystanders.


'Duplex' Loadings based on BP interest me because it seems interesting to me.


It is not any more complex than that.


I have no fouling issues anyway, using Home-Made Lube Wafers, so reduced fouling is not a motive or care which underlay my interest in 'Duplex' Charges.

 

[sonier]

Hi JT-MR-MG42,



'Duplex' Loadings based on BP interest me because it seems interesting to me.


It is not any more complex than that.

That is a good reason in my opinion

 

[Ky Larry]

If there is an advanage to duplex loads, why aren't any of the big boys (Rem,Win,Fed,etc) offering them. They have all the smart people and all the test equipment. Just curious.

 

[Venado]

How do you know none of the big boys don't do it? If a company did do it, they would not advertise it, because they would have the advantage over their competitors. A stratified load has less muzzle flash, more velocity, and less pressure than a comparable velocity regular load. I have been using stratified loads for 17 years, and would not go back.

 

[Oyeboten]

Hi Venado,



The phrase 'Stratified Load' is a very nice choice of words..!


I have heard various wise heads of reloading mention their opinion that 'Buffalo Bore' for one, almost certainly uses a proprietary combination of Powders in attaining their celebrated FPS while staying within S.A.A.M.I. pressure peramiters.

 

[Venado]

Oyeboten, if you will look at my post 'muzzle flash', you will see the proof of what a stratified vs. normal loading will do as far as utilizing your powder charge.

 

[Oyeboten]

Hi Venado,



Where would I find your 'Muzzle Flash' Post?



Anyway...some of my brooding has indeed been about rate of conflagration, elastic rebound or other behavior of the Gasses, duration of peak pressure and when it is reached...

These being in a context always of course, of Bullet Weight and kind, Barrel Length, and diameter of Bullet in relation to Bore.

Reading various incidental things, including occasions of how overly 'light loads' for paper Target sometimes were said to result in a Bullet not even leaving the Barrel ( Pistol ), Loading Density issues when germain to pressure potentials of given Propellents...on and on...

Wondering about these behaviors...

'Stratified' definitely sounds interesting...and or as it may be arranged for any particular Cartridge of course.

 

[Venado]

Hi Oyeboten, do a search using 'muzzle flash' as the topic, it is down the first page. Or do a search for posts by venado.

 

[Oyeboten]

Thanks Venado,


Found it -


http://www.thehighroad.org/showthread.php?t=538268&highlight=Muzzle+Flash


Can you elaborate a little more without compromising discretion?

 

[Venado]

Oyeboten, The flash you were referring to is a stratified load (triplex). I use to use duplex, but found that a triplex load utilizes the powder better, giving more velocity, and less flash. The main powder charge is a powder known for its flash, and it is so slow that it won't even cycle the gun without the pre and post charge. This method is much safer than people trying to get more power out of a standard load by adding powder. I am buying pressure testing equipment next month, and then I will be able to show what is happening.

 

[Tom S.]

WARNING: Thread Hi-jack in progress!

I have Phil Sharpe's handloading book but don't remember anything in it about duplex loads. Can someone tell me where they read about it?

We now return you to the regular thread.

 

[Oyeboten]

Hi Venado,



Very interesting.


My own broodings which preceded my experiments in loading some Black Powder Based 'Duplex' Charges, set out to see how much a given amount of the second powder would effect the FPS, while lessening the BP Charge to that same weight as that of the added 2nd Powder.


I only added very small amounts of a 2nd Powder, and, I thoroughly mixed the two, rather than to have the 2nd one concentrated in any place within the Cartridge.

Results fell upon entirely even and arithmatically progressive lines of increase for the FPS, while, I felt confident, my Pressures remained well within the lower or mid 'SAAMI' range for .38 Special.

I did not take this especially far, having only tried lower end combinations I felt were conservative.

Recoil and Report seemed to co-respond to the incriments of addition, also, if somewhat subtley.

Too bad there are not one-time-use Cartridge Cases, designed to somehow register pressures!


That would sure be handy.


My Test Gun for this was a 3 inch Barrel S&W Model 10.


Still have not found my notes though.


Stratified 'Triplex' Charges of Smokeless propellants of course is a different matter, if having some things on common.


My BP Chares were compressed, thus lending very little free or available Air to the small Smokeless component, which I figured would be alright, since the Smokeless propellant was limited to only some very small amounts, and would be deprived of any ambient Air anyway by the conflagration of the BP.


I was able to work out the increase in FPS for each .5 Grain increase of the Smokeless, which I think turned out to be about like what an added Inch of Barrel increments would have done, with plain BP Charges.


This was very interesting to me...and, to some extent, was also about how an enhanced Black Powder Charge, for a shorter Barrel, could provide Ballistics similar to what a longer or long Barrel would deliver on plain BP...while probably not getting very far into the mid or upper teens of PSI ( in my imagination anyway, since I have no real way of checking).


I imagine quite a few people did this very thing, with whatever care, methodology, or naivete, back when the Smokeless Propellants were still fairly new and limited in variety.

 

[rbernie]

Time to take this two-way dialog to PMs, please.