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CAS TOPICS => The Powder Room - CAS reloading => Topic started by: quigleysharps4570 on January 06, 2012, 01:12:57 PM

Title: Duplex Powder
Post by: quigleysharps4570 on January 06, 2012, 01:12:57 PM
Was thinking of a duplex load for my 45-60...main charge will be Goex Cartridge Grade with the smokeless charge being one of which I have on hand. Here's what's on hand:
Alliant Unique
Accurate No. 9
Accurate 5744
IMR 3031
Hodgdon H335
IMR 4064
IMR 4350
My question is which powder do you all think would be the best for the duplex? Wanting to go 55 grs. of the Cartridge Grade and 5 grs. of the other. Any ideas would be much appreciated.
Title: Re: Duplex Powder
Post by: hellgate on January 06, 2012, 01:47:45 PM
Some of the older loading manuals (Lyman, maybe) have info on using duplex loads. Also you might want to check with the Cast Bullet Association for proven loads. It is easy to get into trouble with the duplex loads so I would recommend published loads from reliable sources. If my memory serves, I believe the shotgun powders were more typically used as the smokeless booster. I've never loaded them as I also believe they are not allowed in SASS shoots and quite a few of the BP target matches. They do, however reduce fouling.
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 06, 2012, 09:01:59 PM
quigley

Of all the powders you list, 5744 would be the one I'd use - 4.2 grs of it wirh 55 BP. Other powders to consider are SR4759 and 4198, long used for duplexing BPCRs.
Title: Re: Duplex Powder
Post by: Lumpy Grits on January 07, 2012, 12:12:22 AM
No need to duplex with the correct load ;)
More issues than it's worth.
LG
Title: Re: Duplex Powder
Post by: quigleysharps4570 on January 07, 2012, 05:30:43 AM
Thanks for the input guys. Believe I'll give 5744 a whirl.
Hellgate I don't do the matches so that won't be an issue...my shooting is all done behind the house or at a friends place on the river, so anything goes.
You're right Lumpy...but I'm just wanting to play.  :)
Title: Re: Duplex Powder
Post by: Junkman on January 07, 2012, 07:32:29 AM
What do you intend to accomplish by loading the cartridges with a duplex load?
Title: Re: Duplex Powder
Post by: Delmonico on January 07, 2012, 07:48:08 AM
More important, has anyone read this? 

http://www.cascity.com/forumhall/index.php/topic,40688.0.html
Title: Re: Duplex Powder
Post by: Lumpy Grits on January 07, 2012, 10:24:43 AM
I shoot/load for BPCR, everyone that I know who started out thinking duplex was the way to go has stopped doing so. Due to issues ranging from cases swelling at the head due to the pressure spike of the smokeless powder, to bulged chambers at the chamber mouth for the same reason.
I will NOT duplex.......It buys you not one thing.
Respectfully,
LG
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 07, 2012, 11:58:48 AM
Anyone who prefers not to shoot duplex loads in BPCRs is welcome to do so. Until such time as I feel I am endangering myself, my guns or anyone else, I shall continue to do so.

There is a history of shooting duplex loading ..... The following from "The Breech-Loading Single Shot Rifle" by Ned Roberts and Ken waters, noted riflemen and ballistic experimenters.

"Some riflemen discovered that loading about 8 grs of Dupont No.1 Rifle smokeless powder in the bottom of the shell as a priming charge, and filling the rest of the shell with black powder with a cardboard or blotting paper wad over it, resulted in as fine accuracy with a breech seated or muzzle loaded bullet, WITHOUT WIPING THE BORE AFTER EACH SHOT, as was obtained with black powder and wiping the bore.
This smokeless powder priming caused the rifle to shoot very clean indeed by preventing the black powder residue from fouling the bore, so that A HUNDRED SHOTS OR MORE COULD BE FIRED WITHOUT WIPING THE BORE and as fine accuracy secured with the last  shot as with the first.
In a very short time, therefore, practically ALL Schuetzen riflemen had adopted it as a priming charge, and many used this duplex loading until the manufacture of Dupont No.1 powder was discontinued in 1926.
This powder did not pit or corrode the barrel when used alone because the residue left in the bore was pure carbon,; also SINCE THE BURNING TEMPERATURE WAS ABOUT THE SAME AS THAT OF BLACK POWDER, IT DID NOT ERODE THE BULLET SEAT OR BORE."

The book goes on to report that the Dupont powder that replaced No. 1 (Schuetzen Smokeless) was even more useful and successful used alone or as a priming powder in duplex loads. Steve Garbe has also written on the topic in his BPCN magazine.

So, unless someone can come up with with something to refute this, I regard the opposition to duplex loads as another of those "... everyone knows ..." gun myths based on ...... ? Strange how those that actually use duplex loads like them while the 'experts' that don't pan them.

When I first began duplexing, I was advised to prevent mixing of the smokeless and BP by compression, negating the use of a separation wad of any kind. I do this, compressing as I would for a 100 % BP load.
Title: Re: Duplex Powder
Post by: Junkman on January 07, 2012, 12:07:56 PM
PJ,

I was not refuting your duplex loading. I wanted to know what the purpose was and you provided me with the answer. Now I know. Good luck with your experiments and please inform us how it goes.  ;)
Title: Re: Duplex Powder
Post by: Lumpy Grits on January 07, 2012, 12:19:41 PM
Duplexing is the answer to a question yet to be asked  ;D
When the smokeless goes off, which is must faster burn than any BP, you are trying to push everydangthing else in that case before the much slower burning BP lights off. That is why you see a bulge in the case head after a few loadings that is a PITA to size down.
Your correct in it's your gun and do as you please.
I for one mhave to much time and $$$ into my Shiloh's to do something this "off" and unneeded.
Respectfully,
LG
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 07, 2012, 03:17:40 PM
Hi 'Lumpy Grits' - I believe that we know each other from the Shiloh forum. That or some impostor has appropriated your alias .... ;>)

I've heard the same argument re: using mag primers in BPCR reloading. I had some mag primers that I started to use up in my 50-70 loads and found no advantage I was aware of. The argument was that the hotter ignition would do what you described - push the compressed charge ahead causing problems; especially in heavily compressed loads with long powder columns.
If it did, you couldn't prove it by me, but I've only used mag primers in 50-70 with no issues. Garbe's experimentation led him to believe that a 'cooler' primer was actually better for igniting BP. It isn't that hard to ignite. What matters is consistency.

I'm not experiencing the case head bulging that you mention. Makes me wonder what you were doing, or are you just passing on anecdotal information? As for any aspect of duplexing being a PITA, when you are acquiring lead, casting/sizing/lubing, sizing/depriming/annealing/cleaning/trimming brass, weighing/measuring/drop tubing/compressing powder charges ..... what's one more step in the process? It's already labour intensive.

You aren't the only one with time and money invested in your Shilohs. I'm down to five, having sold off one of my '63s to guy who just couldn't wait to order one. I've had two Farmingdale locks upgraded by Kirk Bryan, new gas plates fitted on two '63s and returned my new 50-70 carbine to have the stock shortened. They are most expensive rifles I own, what with all the shipping and importation costs and hassles!

As for duplexing being "off", give me chapter and verse to support your claim - like I did. As for it being "unneeded", that's your opinion. The reason it's banned in BPCR silhouette matches is that there is no way to regulate or prove the loads. Regrettably, people cannot be relied upon to be honest, ethical or safe, hence the prohibition of duplexing.

I suggest that if it was safe and accurate enough for turn-of-the-century riflemen, it is still so today.
Title: Re: Duplex Powder
Post by: Lumpy Grits on January 07, 2012, 05:08:51 PM
YUP. that "B" me on Shiloh.. ;D
I have had my best loads with LR match primers(Fed or CCI)
Since you say you are a member of the Shiloh forum why don't you ask there? ;)
Also, use "search" on that site for more information to your ans.
What I related to you was "first-hand" with "eyes-on" helping other BPCR folks at the range. None of them duplex now, BTW.
I will never duplex with what I have seen. No need/want to.
Cheers,
LG
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 07, 2012, 05:44:20 PM
LG

I know better than to ask ANY question on the Shiloh forum. Too many 'experts' for my liking. I mentioned finding an unfired Browning .50 ML 'Mountain Rifle' on the Shiloh site recently and was buried in negative remarks from guys who have never owned one or shot one!
On the Canadian 'GunNutz' site, I got nothing but congratulations from guys that own and shoot one; regrets expressed from those that did and sold them.

One thing I like about this forum is that few members feel the need to feed their egos by listing the rifles they own, the options on them, etc. If anyone is that interested, they can check the Shiloh site or catalog to see what's available.

On the Shiloh forum, I mentioned that I occasionally roll a sized/lubed Lyman 515141 with a .54 calibre 60 gr Pyro pellet for a quick, easy handling paper cartridge for my '63s. Again, I got buried in negative remarks from guys that don't even own or shoot a '63! These same guys shoot '74 cartridge guns with bullet weights and twists that didn't exist historically. Go figure .....

Title: Re: Duplex Powder
Post by: Lumpy Grits on January 07, 2012, 06:21:41 PM
I give you a source for info. that YOU asked about.  :o
Then, you decide that you won't use the source with some BS reason  ???
 Guess you really don't want the truth then...... ::)
LG

Title: Re: Duplex Powder
Post by: PJ Hardtack on January 07, 2012, 09:46:35 PM
Whoa there, Cowboy!

For a start I didn't ask for any information from you or anyone else, I was offering it to the original poster, quigleysharps4570, who made an inquiry about what smokeless powder to use of what he had on hand for duplexing.

I did challenge you to give me 'chapter and verse' to support your claims re: the down side of duplex loading. That means quoting sources and references. I did, to support mine, (and I could give you others) and have had results based on successful empirical experiment and observation. Your opinion is based on ..... ?

If there is any BS flying around, it's coming from your end of the corral, not mine ..... ;>)
Title: Re: Duplex Powder
Post by: Beauregard Hooligan on January 08, 2012, 01:51:30 AM
Easy gentlemen. We can disagree without being disagreeable.

To the OP's question: I don't like the use of duplex loads, mixing smokeless and BP is just a bad idea. I'd either load with BP, or go smokeless. Of the powders listed, I use Accurate 5744 in my .45-70 Remington Rolling Block. I keep my loads mild as the RRB is, like the Sharps, a fairly weak rifle; the books say stay under 18,000 PSI, so I do. I shoot 26 gn of Accurate 5744 under a 405 cast RNFP bullet with SPG lube, or 25 gn under a 500 gn round nose, also lubed with SPG. Those loads are safe even for a Trapdoor Springfield. I poked a hole in a mule deer with the 405 gn bullet a few years back out of my scoped Marlin 1895 lever gun, and it did a nice job of putting that buck down. Here's a couple of photos of my Rolling Block:

(http://i222.photobucket.com/albums/dd244/beauhooligan/RemingtonRollingBlock001.jpg)

(http://i222.photobucket.com/albums/dd244/beauhooligan/RemingtonRollingBlock004.jpg)

(http://i222.photobucket.com/albums/dd244/beauhooligan/RollingBlockTangSight001.jpg)

Now, Can we please get back to a respectful exchange?  ;)
Title: Re: Duplex Powder
Post by: quigleysharps4570 on January 08, 2012, 08:29:25 AM
Nice little Rolling Block BH.  ;)
 
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 08, 2012, 10:24:23 AM
Beauregard

Go back and re-read the postings ..... who was being disrespectful to whom? I don't hide behind a keyboard saying things that I wouldn't say to a man's face. I also back up what I say with facts, references and experience; not hear-say and 'common knowledge' which is often bogus folklore.

Can you give me a reference for "mixing smokeless and BP is just a bad idea"? I thought that I made it plain that the old riflemen used wads to prevent them from mixing and I achieve the same through compression.

You are also forgetting that even Shiloh advises not to use smokeless powder in their rifles unless it is chambered in a cartridge like 30-40 Krag. You and others have found out that the 40% rule (smokeless to BP equivalent) works rather well with some powders (4198, 5744) and is safe in sound rifles, even Trapdoors. I shoot duplex loads, 100% BP and 100% smokeless loads in my Trapdoors just fine.

Some of us have had similar success and experience with duplexing. I'm still waiting for some firsthand knowledge and reports of problems with duplexing.
Title: Re: Duplex Powder
Post by: Beauregard Hooligan on January 09, 2012, 12:39:30 AM
Beauregard

Go back and re-read the postings ..... who was being disrespectful to whom? I don't hide behind a keyboard saying things that I wouldn't say to a man's face. I also back up what I say with facts, references and experience; not hear-say and 'common knowledge' which is often bogus folklore.

Can you give me a reference for "mixing smokeless and BP is just a bad idea"? I thought that I made it plain that the old riflemen used wads to prevent them from mixing and I achieve the same through compression.

You are also forgetting that even Shiloh advises not to use smokeless powder in their rifles unless it is chambered in a cartridge like 30-40 Krag. You and others have found out that the 40% rule (smokeless to BP equivalent) works rather well with some powders (4198, 5744) and is safe in sound rifles, even Trapdoors. I shoot duplex loads, 100% BP and 100% smokeless loads in my Trapdoors just fine.

Some of us have had similar success and experience with duplexing. I'm still waiting for some firsthand knowledge and reports of problems with duplexing.

I don't care who said what, it was the tone that could have been more polite. I try and be at least polite and civil no matter the provocation, and that's been working well for quite a while. There is certainly nothing lost by avoiding discord.  :)

My comments about duplex loads are based on my personal opinion that it complicates loading and safety. Call it a gut reaction, but I would avoid using duplex loads unless there was powerful evidence that it significantly improves performance without sacrificing safety. I'd be interested in learning more about it, in a friendly and companionable way.  ;)
Title: Re: Duplex Powder
Post by: Trailrider on January 09, 2012, 10:14:30 AM
I do NOT shoot either duplex loads or BP in my cartridge guns, but an interesting aside:  For many years (don't know if it is still done) ballistic actuated ordnance devices (ejection seat cartridges, takeup reels on F-104 jet fighter ejection seat boot retrators, etc.) utilized A4B BLACK POWDER as an initiator charge for the smokeless final stage propellants and gas generation devices! Just thought you might like to know.  The BP charge was separated from the main smokeless grain (not grannules, just a single grain).
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 09, 2012, 12:13:17 PM
Beauregard

Point taken re: 'who flung dung'. I believe I have a record of being civil and erudite on public forums, but I do respond in kind when attacked or abused. Cyber bullies are no different than the school yard variety.

Having recently blown up your gun, I can understand your apprehension about duplexing or any other reloading practice that takes you out of your comfort zone. Good - that fear will keep you safe.

How much more evidence do you require that duplexing "significantly improves performance without sacrificing safety"? My experience, that of others and references such as I quoted from "The Breech-Loading Single-Shot Rifle" by Major Ned Roberts and Ken Waters are obviously not impressing you.

If long strings of duplex loads without adverse effects on rifle, brass or shooter, great accuracy and minimal barrel fouling don't convince you, what will it take? Do not construe this an attempt to convert you to duplexing against your better will and judgement. A man's gut is one thing in life that will not lie to him. I trust my gut feelings implicitly, and I don't go where it tells me not to.
You could contact Steve Garbe at Black Powder Cartridge News for his views on the topic. He knows whereof he speaks and does so with 'been-there-done-that' authority.

As for it being an unnecessary complication, it is just one more step in an already complicated process. I first charge cases with the smokeless, block check and then charge with drop tubed BP and compress. Since I am using my 'lectronic Lyman DPS III powder dispenser for the BP, I have sufficient time between charges to drop the smokeless charge, but I feel safer not doing so.

That's me listening to my gut feeling .... ;>)
Title: Re: Duplex Powder
Post by: Beauregard Hooligan on January 09, 2012, 02:55:01 PM
Beauregard

Point taken re: 'who flung dung'. I believe I have a record of being civil and erudite on public forums, but I do respond in kind when attacked or abused. Cyber bullies are no different than the school yard variety.

Having recently blown up your gun, I can understand your apprehension about duplexing or any other reloading practice that takes you out of your comfort zone. Good - that fear will keep you safe.

How much more evidence do you require that duplexing "significantly improves performance without sacrificing safety"? My experience, that of others and references such as I quoted from "The Breech-Loading Single-Shot Rifle" by Major Ned Roberts and Ken Waters are obviously not impressing you.

If long strings of duplex loads without adverse effects on rifle, brass or shooter, great accuracy and minimal barrel fouling don't convince you, what will it take? Do not construe this an attempt to convert you to duplexing against your better will and judgement. A man's gut is one thing in life that will not lie to him. I trust my gut feelings implicitly, and I don't go where it tells me not to.
You could contact Steve Garbe at Black Powder Cartridge News for his views on the topic. He knows whereof he speaks and does so with 'been-there-done-that' authority.

As for it being an unnecessary complication, it is just one more step in an already complicated process. I first charge cases with the smokeless, block check and then charge with drop tubed BP and compress. Since I am using my 'lectronic Lyman DPS III powder dispenser for the BP, I have sufficient time between charges to drop the smokeless charge, but I feel safer not doing so.

That's me listening to my gut feeling .... ;>)

Thank you for the reply. I obviously need to learn about duplex charges, and "The Breech-Loading Single-Shot Rifle" by Major Ned Roberts and Ken Waters seems to be a good place to start. I'll find a copy, and start reading up. When I have questions, if you don't mind, I'll drop you a question or two. I'm at the "it's never too late to learn" stage in life. Thank you for taking the time to help me, and the others that are reading this, to learn a firearms science that is obviously worth learning. You can teach an old dog new tricks. Thanks again. ;)
Title: Re: Duplex Powder
Post by: w44wcf on January 10, 2012, 07:59:20 AM
P J Hartack is entirely correct  when it comes to duplex loading.  In the early days, DuPont No 1 Bulk smokeless (introduced in 1893) was used. It had a burning rate similar to today's 4198.

"Swollen case heads" can only come from USING THE WRONG SMOKELESS POWDER! DO NOT USE anything faster than 2400, nor more than 10% of the total charge weight.

Back in 1980, when the 3rd Lyman Cast Bullet Handbook came out, they included data on some duplex loads in the 45-70 using SR4759 powder including pressure data.

That data proves that the practice is totally safe when the proper components and ratios are used. ;D

w44wcf
Title: Re: Duplex Powder
Post by: Grapeshot on January 13, 2012, 09:17:09 AM
I have read Paul Mathews books on the .45/70 and loading Black Powder and he used an SR prefixed powder.  I do not have that reference in front of me as I am in Iraq.  However, I have read some of the works of Elmer Keith and IIRC using a Charge of 10% of the total weight of the powder charge required, 4Fg was found to be good to get a clean burn because of the 4Fg's burn rate.

I own and shoot a Navy Arms Rolling Block .45/70 and have used this combo both with Goex 2Fg and Pyrodex and a Winchester .45-60 that I've tried with this formula and found that I can extend my accurate shooting to around 10 -15 rounds before having to punch the bore with a damp patch.

By definition, is this recipie of 4Fg and 2Fg a duplex load?
Title: Re: Duplex Powder
Post by: PJ Hardtack on January 14, 2012, 10:56:08 AM
Grapeshot

Keith may have been aware that there were even triplex loads of compressed BP made up during the Civil War. The idea was higher velocity and a cleaner burn by utilizing powders with different burn rates - fastest at the bottom, slowest at the top.

It didn't last, as it was a PITA to manufacture on a mass basis, and the advantage gained was insignificant.
Title: Re: Duplex Powder
Post by: Dick Dastardly on January 17, 2012, 08:03:56 AM
The Lyman book lists a 5% charge of IMR 4759 powder under the black powder.  I've been using it with total satisfaction.  Since I shoot Big LubeĀ®LLC bullets exclusively, I find that the copious quantity of lube along with the duplex load gives me excellent accuracy with no need to swab the bore, use blow tube or push patches thru.  My rifle is a fine old Remington Rolling Block that's been rebuilt and barreled with a Green Mountain 45-70 barrel.

I'm having equal or better results with my Legendary Frontiersman 38-55 and the same kind of duplex loads.  The 38-55, for reasons I don't understand, is one of the most accurate guns I've ever owned.  It shoots bp loads and duplex bp loads equally well.  Of course, I'm also shooting Big LubeĀ®LLC bullets in it.

So, Lyman has detailed a fine duplex load.  NO, I wouldn't go experimenting with unlisted duplex loads.  I leave that for the brave of heart.  But, the load I found in the old Lyman manual is serving me well.

DD-MDA