Was doing some load development for my AR last night, and it seemed like W748 was too bulky. I ran out of room in the case before max load was attained. W/ H335 the max load left room for 5-6 gr more powder. I know the label says "NEVER MIX POWDERS", but I guess I'm thinking outside the box. Of course I'd start low and work up. Does this seem like a feasible idea or am I asking to ruin my gun and injure myself?

Really bad idea!

DON'T EVER EVEN THINK ABOUT TRYING IT!!! Life's way to short!

No reasonable charge of W748 ever filled a .223 case. What is your source?

Turn the light on and follow the manual. Not just for yourself but for anyone who stands near you when you pop a cap.

Why not? Smokeless powder of similar burn rate should behave together, shouldn't they?

You are not thinking outside the box but if you mix powders you will probably find your way into a pine box.

Elmer Keith supposedly tried this 60+ years ago, called them "Duplex Loads". This was back when the powder selection for reloaders was very limited. He received a lot of critcism for suggesting this practice and later distanced himself from it.

It's a bad idea because you are venturing into the dangerous unknown. Different lots of the same powder can be quite different! 1 + 1 might equal 3 if you start mixing stuff. You can go from 50,000 PSI to 70,000 real quick. Why risk it for a couple bucks worth of powder?

Carverelli,

There are a few people on the board here who have experimented with duplex loads, apparently you can get some spectacular velocities when everything goes right. My understanding is that while you can get respectable velocity the repeatability is much harder to nail down, so accuracy suffers-sometimes a lot. Maybe someone will post some real-life experiences but there are more bad ones than good ones. I know the only two people I have personally talked to with any experience have both damaged rfles by experimenting.

I wouldn't even think of doing such a thing unless I had rifles to wreck and a very long string! Even if you find a "safe" load that you are happy with the chance of being able to repeat that exact load and trust it inches from my head is one I would not take.

I don't post many replies any more but I feel in this case the more deturance you get the better.

Thought I would comment.

If you take all of the dangers out, which this is, the simple facts are that we strive for consistant, efficiant burning. Not spuratic, uneven burns. Just seems like it would not even be worth waste of good powder. I would guess that accuracy would suffer as well. IMHO

Regards
JAG

Out here in South Africa we have a dearth of powders with suitable burning rates for certain calibres.

For example we have a "fast" extruded powder called S335, and a "slow" extruded called S365. They are roughly equivalent to IMR3031 and IMR4350, respectively. What we lack is a medium performer like IMR4064.

Sooooo.... we duplex. I use a 50:50 mix of S365 and S335 and in my 22-250 it gives excellent results with the heavy 69gr BTHP. Top speed is 3400fps with no pressure signs and 0.3 groups.

It is not a problem provided you are careful and providing you weigh out each charge individually. I use an RCBS digital powder dispenser and measure combination. I load up 100 charges of 16.5gr of S335, the top up with 16.5gr of S365. I dump the complete charge back in the pan to check but more to "mix" the two powders. It is not a compressed load. Time consuming but worthwhile.

Cardinal rule is not to mix ball and extruded powders.

A lot of controversy exists between us as to what is better, to put in the fast powder first or last. I reckon in an uncompressed load it is immaterial, they will mix with normal handling. Nobody has been able to demonstrate the difference (not to me at least)

I used to be very wary of it until I went to a reloading workshop where the local reloading fundi Mauritz Coetzee of VLT Weapons did a demo for us.

For the American shooting fraternity this is obviously unnecessary you have an excellent range of powders to choose from.

Cheers

Pete

P.O. Ackley used duplex loads when doing his tests on the various military rifles to see where their blowup point was.

Duplex loading requires altered cases with a burn tube inside each case. Only those experienced in that type of relaoding practice should attempt to do so. You are certain to injure yourself by blowing up the rifle with no duplex loading experience. Duplex loading loading will work but you must know exactly what the hell your doing first. If you do not know before you start don't attempt it period end of sentence. Duplex loading is only practiced by experts in the reloading field. Novice reloaders have no business fooling around with duplex loading.

Back in the early 70's Dick Casull experminted with "triplex loads" in the .454 Casull in an attempt to get ultra high performance from that cartridge. He managed to blow up and damage several guns in the process. If I remember correctly he loaded 2 or 3 grains of Bullseye over the primer, followed by 4 or 5 grains of Unique, or some other mid range powder, then over that he loaded the main charge of several grains of 2400. The problems came when the powder got mixed up in the case from rough handleing or dropping the cartridges. The load would then detonate, rather than burn at a controlled decreasing rate, as was supposed to happen. With the newer modern slow burning powders now on the market, this type of foolish expermintation is no longer necessary. Bill T.

Cadaver, I mean carverelli, what sort of chamber pressures do you anticipate with your home brew?
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Take your time....
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The problem is this - you have no idea. Even mixing similar burn rates does not mandate consistent nor safe results. In fact, what Elmer Keith and P.O. Ackley discovered was duplexing does not always net uniform chamber pressures. They experienced very unexpected results - this is coming from some pretty wise folks mind you.

Can you safely duplex powders? - Yes you can. There are some powders that can be used to duplex. However, this is not a universal rule. Not all powders like each other. Unfortunately, there is not a reliable source of information or pressure tests to reference.

What I find particularly interesting with your experiment is - in the US we have a tremendous selection of �appropriate� powders. There is not any sane reason why anyone (smart or otherwise) should be playing with duplex loads. If there is a gain to be made, the powder companies with their unlimited wealth of knowledge and budgets generally come up a safe solution. Armature powder pioneers with limited knowledge and even more limited common sense generally do not make correct assumptions.

However, if you really like living on the edge and just love that rush of adrenalin each time you pull the trigger, go have some fun. However, for the sake of your follow shooters, please do NOT run your experiments on a public range where you will endanger others. Find some nice quite patch of woods to play. Make sure you leave your loading notes in the car - this makes the autopsies a lot easier. Especially when they filling out the cause of death blank. They can simply enter - �stupidity�.

Have fun....

(Sorry for the sarcasm - I could not resist having a little fun at your expense)

[ 11-09-2002, 20:21: Message edited by: Zero Drift ]

DON'T

What are you trying to achieve? More velocity,100% load density? There are powders that will do this for you without mixing up some wildass witches brew. Email me if you need AR load data.

I just use pure nitroglycerin in my loads!

He must be jerking our chains.

6gr. of room is still 75-80% density. No shortage there.

Those using Elmer and Ackley references should acknowledge that those guys were at the forefront of development and not just a couple weekend hand loaders andthat was at a time when the powders available were not nearly as diverse as they are today.

Why not? Because its very risky, and with the powders available today there is no reason for it outside of simply being cheap. Im about as frugal as they come but Ive got some mixed powder from dissasembled loads and it will NEVER see the inside of one of my cases again. Use the H335 as it is or break down and buy some different powder.

Gents,

I always love the "don't do it, you'll put your eye out" responses.

It was very nice to hear about the South African reloaders use of duplex loads. Also Elmer Keiths, and Casulls experments.

Without people willing to experiment, where would our advances come from?

My only suggestion, for the 'naysayers', is to make your safety comments and suggestions, then wish the fellow good luck. After all, he was seeking real life experience, not our permission.

BW, I can agree with what you are saying, without people willing to take chances there would be very little advancements but with all do respect to carverelli the fact that he even asked such a general question about duplex loads is a good indication that he is not ready to be on the forefront of discoveries on this subject.

He did also ask was he asking to ruin his gun and injure himself. What do you think?

If you understand the chemistry of nitrogylcerine and nitrocellulose and the physics of how it ignites under various pressures then by all means . . . go for it.

Ignition characteristics vary as pressure varies. You want to demonstrate this, pour a charge out on your driveway and set a match to it . . . Poof and very little pressure.

Search "intenal ballistics" online a bit . . . not the reload stuff . . . take a look at military artillery and structural engineering stuff.

If you think mixing powders is a good idea, there's a good chance you're too stupid to really understand what it is you're doing.

Gentlemen,

I think our friends in the US cannot imagine the crazy things we do to reload our ammo.

This really stems from the point that we are unable to find the abundance of components you have in the US.

In my country, as well as some other African countries, reloading components are not easily found, especially powder.

Personally, I have never mixed powders, except in very large cases where we got hangfires. To illiminate that we had to use about 2 grains of Bullseye at the bottom of the case to help the large charge of powder ignite properly - check our loading data for the 577 T.Rex.

We use reclaimed powder from any old ammo. In fact, we find a use for ANY smokeless powder.

I had a call from someone once who wanted to know of how to dispose of some ammo which had gotten wet. I told him to bring them over, and I will be happy to dispose of it for him. He said he needed a truck, as he had a LOT of ammo.

We sent our truck to collect it, and got back over 20,000 rounds of 12 gauge ammo, several 1000s each of 7.62x39, 9mm Luger and 7.62 Nato ammo.

We managed to save a few of the above, but most had to be disassembled, and all the parts reclaimed.

We found that most of the damaged ammo had corroded primers. Those we took out the bullets and powder.

The shotgun shells we kept the powder and shot.

From the 7.62x39 ammo, we got what looked like six different types of powder. Some were ball and some were stick.

We put all the ball powders together, and all the stick powders together.

We are still using these for our 222 and 223 fun shooting, as a cheap source of powder. It seems all these had very similar burning rate to 4198.

The shotgun powders we use for pistol ammo. All are used with reduced loads, and I think we must have fired several thousand rounds, and never had a single problem.

/

have fun and send an address where we can send flowers!

We tried a mix of 700X and H870 in our overbore cal. rifles (240 Gibbs,6.5 Gibbs,6.5/300Wby) but had trouble with getting consistant velocities. These were compressed loads with the 700X over the primer. Then we got some RL25 and gave up on the mix idea.If you use your head I doubt you will have any rifle parts imbedded in it but for your application there are so many powders available I wouldn't think it's a good idea.Mark

As Saeed said it can be done start with the low end with the fastest powder you mixed and work up. My Ieal hand loading book has duplex loads listed. but in they USA now we have such wonderful and aviailbitys of power no need to play around with such things.

Not to encourage but I think the only "safe" way would be to purchase an Oehler pressure testing package and start from there. I will get one of these...in about 4 years. I have always wondered what the effect of putting 3-4 grains of 20mm cannon powder in an overbore cartridge would be. Like a .264 Winchester? Keep the pressure curve up for a greater length of time? I don't know but would like to, the only way to find out is as been suggested; a long string but with Oehlers set-up.

Oh, Hell and horsefeathers!

What's the big deal about some simple experimenting with duplex loads??? Why, for .223 Remington, a fellow would have LOTS OF FUN with a half-and-half, full-case charge of Bullseye and Unique! Yessssssssssssssiiirrrrrrrrrrrreeeeeeeeebob, that's the way to go. And what the Hell, you could even start doing TRIPLEX loads with Bullseye, Unique, and Red Dot!!!

*** LEGAL DISCLAIMER ***

I am in no way responsible for anyone taking my advice. Any problems arising from taking said advice can be directed to my attorneys, Dewey, Cheatum, and Howe.



[ 11-11-2002, 02:53: Message edited by: Russell E. Taylor ]

Hobie, Guess that you have never used W748 in any .223 case. If you had tried it, you can get 30 grs. in some brands of cases and still run out of room. BTW have been using W748 in the .223 for over 20 years and it's still my favorite.

We have a local paper that runs a bunch of fantastic stories like the dumbest criminals, the guy who tries to rob the donut shop with a cop car outside.... He also has one titled "thinning the herd". Don't fall into the latter catagorie. Early duplex loads were a small charge of smokeless powder under black powder to reduce fouling. This was not a load issue. The point is ...Whats the point? If you are trying to develop a load you want as much consistancy as possible to tune you results. mixing powder..... well, just chuck the scale forget anything that makes sense and just fill every case to the bottom of the neck with what ever you have. NOT. Most every one here has to agree that the guy who has done this is plain LUCKY> Pete said he has done this. Anyone reading this must understand that he HAS MADE HIS OWN POWDER and he is obligated to test it and work it up like he brewed it up in his own lab. My comments are not posted here for the the questioner. If he has not gotten it by now, he has no business loading at all. My comments are to the other readers of this thread who may think if Pete can do it maybe there is something to it. If you can't load it according to proper levels in the proper protocol then buy factory and sell your gear on ebay. (I wonder if Pete will cover damages from his formula ......?) JBMauser.

All right, so the consensus is that I shouldn't do it, ok nuff said. While I think that carefully loaded "duplex loads" could be safely worked up. The idea that they wouldn't be consistent bothers me. the biggest reason I reload is for consistent accuracy. the other being economics. My AR will shoot remanufactured Black Hills 50 gr v-max loads into a 1/2 " @100 yards w/ little trouble. But, some loads I tried the other day w/moly 50 gr v-maxs beat that by a little. 26.4 gr of H335. Velocity was around 3450. I will try a little less H335 and a little more and see what happens to my groups. I'llKeep ya posted if you care. I was under the assumption that nearly full case capacity was crucial to the best accuracy. Next thing before i go back to the range is a better rear bag. Was using 3 sand bag stacked on top of each other to get the right height(lead shot sacks filled with sand) They kept falling off and I'd have to reset. The rifle seemed to move a little different w/ each shot. Still 4 shots were touching -a horizontal string

Whatever...

carv,

Most would agree a high load density is better, but in my experience once density is over about 75% bullet seating depth is going the have the greater effect on accuracy.

You will need to work within the confines of the magazine of course.

Hey I'm not the only South African duplexing loads, there must be hundreds of reloaders doing it, simply because there is no IMR4064 equivalent on the market.

In any case, 33gr of my 50:50 mix of fast S335 and slow S365 is 1 grain over the recommended top load for S335 ALONE and a 70 grain bullet, so I don't see how I can be flirting with danger.

I tried S365 alone - couldn't get enough in the case to get past 3000fps and it fouled.
I tried S335 alone - too much pressure with not enough velocity. The best powder Sierra recommends for the 69gr bullet in 22-250 is IMR4064 - that's what started this.

What is essentially happening in the case after ignition is an extended time pressure curve. I'm getting excellent accuracy and no pressure signs at an excellent velocity for this bullet (3400fps from a 26" barrel)

These loads are very consistent, which comes from the individual weighing and mixing of each charge.

The only visible difference between the two powders is S335 is a tad shorter and less diameter than S365.

The factory and other advocates recommend a sliding scale - if you want more bulk, add slow powder, and take away a like amount of fast powder, so that your total powder weight remains constant.

Cheers

pete

Keith NEVER advocated mixing powders, his "duplex" (a very misleading name) loading system entailed using a tube inside the case to carry the "fire" from the primer to the front of the powder column.

The idea was to use the pressure from the burning powder to keep the powder inside the case so that it would all burn propery under the designed pressure instead of having it blown out into the barrel where individual granules could get left unburned. It's supposed to have added 2-300 fps to the 50 BMG during testing at Ogden arsenal during WWII, but Keith really wanted it tested in small artillary (37-155 mm cannon) where he felt it would give better results. He finally decided that the fine machine work needed to fit the tubes into the brass cases wasn't worth the effort for small arms; but that cannon shells had the space inside to make it worthwhile. Read his autobiography "Hell, I was There" as many of his older books mention duplex loading without explaining it as he felt it was a true advantage that shouldn't be revealed to enemies of the U.S.

The "triplex" loads used during early development of the 454 Casull were a crutch as there wasn't a proper powder for the case size/bullet weight and Dick Casull was trying to reach peak pressure faster, and maintain it longer, than any single powder could do. Long before the 454 Casull became a factory offering the triplex loads were dropped in favor of WW296/H110 and similar bulk powders only available to the factories.

Volume 1 "Handbook for Shooters & Reloaders" P. O. Ackely 1962, page 521:
"Pistol and Reloading Tables 454 Magnum ... developed by Jack Fullmer and Dick Casull...The clyinders made of special high tensile strength alloy steel, properly heat treated to withstand the high pressure developed by the special duplex load.

Obviously, great care must be exercised when working with the duplex or triplex loads. When loading the following loads with the various powders, the powder charges are introduced into the case in the order given, and held in place with compression. The primer pockets are altered to accept the Remington 9 1/2 primers.

230 gr bullet[Unique, 2400, Bullseye]2000 fps
250[Unique, 2400, Bullseye]1890 fps
300 [2400, Unique]1710 fps

.. 20" Win 1892,
230 gr 2315 fps..
250 gr 2185 fps"

I agree with CMcDermott about the old tri plex loads are not as good as H110/W296.

I think LIL'GUN is starting to supplant H110 in some loads now.

I think I might try some modern powder duplexes, like Power Pistol, LONGSHOT, and LIL'GUN.

I use duplex load as well . If I has the choice of propellants available that you have in US or Europe I would not be doing it .
Yes , I am South African and choice is limited to Somchem .

There seem to be three different approaches :
1. A few grain of ( Red Dot ) shotgun powder above the primer followed by the main charge . This is to facilitate the ignition of a slow powder in a large capacity case .
2. 50:50 or 60:40 mix of two powders to try and achieve a burnrate that may be between the two .
This approach seems to be the most used . The slower powder near the primer . see Pete's post .
3. The last approach is to add some (2400) slow pistol powder ( about 10 gr) on top of the main charge . ( not on the primer ) . Start very low and work up carefully - only increase the main charge and keep the pistol powder charge constant.

Rules :
Never mix ball and extruded
Try and keep faster powder away from primer .
BE VERY CAREFUL !!!!!!!!!!!!!!!!!!!

EG :
375 H&H : Duplex S335 (IMR3031)and S365 (IMR4350) 50:50 mix
45/70 : S335(IMR3031)against primer with 10 gr of S265 under bullet .

I do not advocate the use of Duplex loads .

Ben

Very interesting topic, on the edge, but still interesting.

[ 11-14-2002, 07:38: Message edited by: Hutt ]

About every 6 months this goofy topic bubbles to the surface. Last time it happened I got into an argument with a couple of South African fellows, possibly Pete Millan. Anyway, he/they went out and tested their duplex loads and not only lived but got pretty good results.

Then as Saeed points out, we can't imagine some of the crazy powders they get their hands on to experiment with.

I am perfectly willing to accept that with CERTAIN POWDERS and in CERTAIN COMBINATIONS one can probably enhance a load. I don't have a problem with that concept.

But as far as American Powders go it can be like opening door 1,2, or 3 to find out which one the tiger is behind!

With OUR powders, it's a damn stupid practice and I suspect Carverilli is just jerking chains. But in case he is really serious and he thinks it prudent to blow off the advice of about 20 members here on AR and try his luck with some powder mixing.....GO FOR IT!


I tried this many years ago when I was a Know-It-ALL college boy. I'll never forget that evening on the firing range with my little chronograph. Velocity and pressure were all over the charts. It didn't take a rocket scientist to figure out I was playing with something I couldn't control.

If Carverelli thinks he is bigger and smarter than all the rest of us, go do it and quit talking about it. Don't take our word for it!
Maybe all of us are just jerking YOUR chain!

[ 11-14-2002, 08:42: Message edited by: Pecos45 ]