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waksupi
05-24-2006, 11:01 PM
OK, got a question for you all.
When you duplex a load, why is it important that all the "flash" powder remains at the rear of the charge? It would seem that the ignition would be fairly instantaneous with all the powder, regardless of position. Wouldn't the faster powder still clean the bore, even though intermixed? I know everyone always says to keep the fast stuff over the primer, but has anyone ever really experimented with this, or is it an old wives tale that we follow?
I'm too much of a coward to try it in my rifles, but wouldn't be surprised if someone here, has tried it.

45 2.1
05-24-2006, 11:17 PM
The oldtimers used up to three different blackpowders in layers and i've read that they mixed them also. For trial in very strong rifles only though, we want to keep reading current posts from you.

On another vein, have you heard of activated blackpowder? Discussions about it over on British Militaria.

454PB
05-24-2006, 11:22 PM
You are probably talking about using a "flash" powder in BP cartridges, and I have no experience with that. I have, however, done some experimenting with mixing ball smokeless powders to alter their burn rate. This was done on a small scale, and for the most part was more trouble than it was worth. Nothing exciting happened, but it was sorta spooky!

Flame suit donned....

StanDahl
05-24-2006, 11:47 PM
This may not entirely relate, but it's my specialty (not relating to a topic completely, that is) ...xxgrampa recommends a reverse duplex for BP: 85% regular bp with 15% FFFFg on top of the charge. Easier on the bullet, burns clean.

waksupi
05-25-2006, 12:29 AM
Never heard of activated BP. I would like to hear more. And, I will try XXgrandpa's suggestion on reverse duplexing.
What I actually had in mind, was, say 4-5 gr. 4064, or whatever, in a case full of WC 860, or WC 872. My K 31 better look out, it may find out how it works!

454PB
05-25-2006, 12:58 AM
Coincidentally, one of the powders I was using was WC860, the other was H-335.

StanDahl
05-25-2006, 01:27 AM
I just got off the phone with my shooting guru xxgrampa, and he says that reverse duplex can work well with smokeless and bp - with the bp at the bottom and the smokeless at the top. Not always, but more often than not. I didn't see your clarification in time, so I got nothing there on smokeless on smokeless. Stan

9.3X62AL
05-25-2006, 10:37 AM
Ric--

I haven't tried any smokeless duplex method other than the faster powder first into the case, with slower powder making up the bulk of the load. Why that is recommended--I have no idea. My thrust was consistency--same elements in the same position and anchored that way by 100% loading density or a little compression. I don't know if thorough blending would accomplish the same thing, or not. I suspect it would--but the act of blending might even produce new variables, like powder granule breakage or displacement of deterrent coatings. I do know that going from 3.0 x 4198 + 48.0 x WC-860 to 6.0 x 4198 + 46.0 x WC-860 lifted velocities from the 1000 FPS level to the 1300 FPS level in the 45-70 with the Lee 405 RFN plain base, and gave very little fouling in the bore--unlike the former load. I say this to illustrate that relatively small changes in fast/slow powder ratios can really change the ballistic outcome, even in a cavernous case like the 45-70.

Larry Gibson
05-25-2006, 12:50 PM
OK, got a question for you all.
When you duplex a load, why is it important that all the "flash" powder remains at the rear of the charge? It would seem that the ignition would be fairly instantaneous with all the powder, regardless of position. Wouldn't the faster powder still clean the bore, even though intermixed? I know everyone always says to keep the fast stuff over the primer, but has anyone ever really experimented with this, or is it an old wives tale that we follow?
I'm too much of a coward to try it in my rifles, but wouldn't be surprised if someone here, has tried it.


Assuming you are refering to BP duplex loads(?). I have been duplexing for my TDs for some years. Wolf's book on reloading for the TD is a good source of info and a good explanation of duplexing. In the 45-70 I use 7 gr of 4759 under 52 gr of Goex Cartridge witha Rapine 460500. This load shoots sub 2 MOA all day long without cleaning. For the 45-55 load I use 5 gr of 4759 under 49 gr Goex Cartridge and the Lee 405HB bullet. Again accuracy is excellent and you can shoot 100+ rounds without cleaning or having a fouled bore.

As to duplex (some have done triplexing) loads with smokeless. This seems to come around every decade or so. I imagine the results will be no better than they have been in the past. Hopefully not too many guns will get damaged this go around and no one will get seriously injured. If you go back far enough you'll find Elmer keith and several of his associates did quite a bit of duplexing. Casull (SP) of .454 fame duplexed and triplexed .45 Colts on his way to finding success with a larger cartridge using more of just one powder. That right there should tell us something.

As to mixing powders to alter the burning rate I have to ask; what the hell for? Just get an appropriate powder of the burning rate you want. It's not like there is a shortage of powders these days.

I have mixed odd lots of left over powders of the same type (i.e. ball powders) of the same relative burning rate to create a large "lot" or batch of powder. The factories do the same thing. I always work up loads for that "lot" or batch by using the starting load for the fastest burning powder that was in the mix. As expected the max safe loads fall between that for the fastest powder and the slowest powder of the mix. I only do this with various lots of milsurp 4895 to make one lot. Also with ball powders falling between 2230 and 748 including ball powder from pulldown 5.56 and 7.62 ammo. I usually mix these when there is enough odds and ends to make up a jug of it (6-8 lbs). Again let me say I mix these not to alter or create a new burning rate but to use the powder in a safe manner. I always work up loads for that new lot as with any new purchase of bulk powder as mentioned.

I'm not saying not to experiment but a carefull research of what's been done before will give you a good idea as to whether there is a real benifit or of the risk involved. As you can see I do some but don't go to any extreme.

Larry Gibson

felix
05-25-2006, 01:07 PM
Black powder burns according to proximity of the individual granules. Therefore, smaller granules provide for a faster burn. Mixing black powder will alter the burn rate in a predictable manner, assuming an even mix. Not so in smokeless. Not a proximity burn. Getting smokeless powders throughly mixed is the problem, and wave patterns created during the burn can cause each shot to vary too much. This is why WW630 was taken off of the market. I got in the habit of throughly mixing the stuff before placing it into the hopper, and very gently to preserve the coating deterrents. Casull initialized his 454 development using a tri-layer sandwich, using Unique/2400/Unique compressed by the boolit. Very bad ES's. Smokless powders need to have the same granule size and specific gravity to be mixed properly. Various lots of the same powder usually fit the bill. On the plus side, just about all of the most exquisite wiskeys of the world are blended. ... felix

waksupi
05-25-2006, 08:34 PM
I've been using a kicker behind WC 860 in my .45-70 Sharps, with great accuracy, running around an inch and a quarter at a hundred yards.

What I was getting at, say you have a cartridge with a capacity of 50 grains. You are shooting 40 grains of main charge, with five grains of kicker powder, leaving 5 grains worth of space in the case. The different powders could freely migrate through the load. No compression to hold it in place. What would happen?

felix
05-25-2006, 08:43 PM
Ric, that would be a SEE condition which might not ever occur in your lifetime. However, it could happen on the first shot. Use PSB filler and very slightly compress it. SEE conditions don't really exist with BP because there is no real locked up energy in the granules that can be released all at "once". ... felix

Cliff
05-25-2006, 11:02 PM
Well Paul Matthews I believe talks of doing this with some of the slow stick powders in his strong .45-70's and .458's. He uses a charge of something like Unique to get a clean burn on something like surplus 4831. I don't remember all the details but he evidently had good luck with it. The quick burning powders aids the ignition of the slow powders for complete burn. As for black powder I have experimented to some extent using something like Unique and usually double F Dupont or its equivalent. I tried it on the bottom next to the flash hole, got clean bore and clean cases. Tried it on top of the black powder and got very little smoke but a lot more fouling. I mixed it up before loading it and it was similar to puting the Unique next to the flash hole, I also placed a small soda straw in the case filled it with Unique and poured the black around the straw and then removed the straw, but it didn't change much, no fouling and it did seem to reduce the smoke some. Then I quit. Have fun and be careful. ATB

JohnH
05-25-2006, 11:45 PM
Ric, I've played a fair bit with duplexing 860, using powders from 5744 to 4895 as the "igniter". Best results so far have been with 4 grains of 5744 and 4 grains of 680 under 50 grains of 860 and the Lyman 379449. Of course this is in my 375 JDJ Encore rifle. Let us say that the loads are energetic. 2 grians of 4895 under 53 grians of 860 gives me 1530 fps and low ES's, on the order of 30 fps, but one day the load will shoot fantastic groups, the day so so. The 5744 or 680 loads are more consistant in accuracy but don't produce the "Wow look at that" groups the 4895 sometimes does. There is a noticable difference in velocity between non-duplexed 860 and duplexed, but so far, I've not beaten the accuracy of straight 2015, 3031 or 4895 loads, so while the duplexing is fun to play with, I don't expect it to produce any miracles, but they are fun loads.

Bass Ackward
05-26-2006, 08:12 AM
Without considering the merrits or risks for duplexing, using a slow / fast strategy works better when the goal is for producing velocity. Mostly in smaller capacity cases where it is the most dangerous. It probably is capable of accuracy too, but look at the amount of variables you increase by it's use.

Duplexing with fast / slow is a strategy for utilizing a .... normally too slow of a powder for a cartridge.

We have proof that a powder column does not burn instantaneously. Therefore, seperation produces the intended purpose that allows you to call it duplexing. If duplexing is the strategy, then compression is the only method to ensure it stays seperate. Otherwise, you aren't duplexing, just mixing powders.

buck1
05-27-2006, 08:53 PM
Without considering the merrits or risks for duplexing, using a slow / fast strategy works better when the goal is for producing velocity. Mostly in smaller capacity cases where it is the most dangerous. It probably is capable of accuracy too, but look at the amount of variables you increase by it's use.

Duplexing with fast / slow is a strategy for utilizing a .... normally too slow of a powder for a cartridge.

We have proof that a powder column does not burn instantaneously. Therefore, seperation produces the intended purpose that allows you to call it duplexing. If duplexing is the strategy, then compression is the only method to ensure it stays seperate. Otherwise, you aren't duplexing, just mixing powders.


I had not thought about that, It would have to be compressed I guess. ....Buck

BruceB
05-27-2006, 10:02 PM
I believe that the description from Bass is right on the money.

I've only used duplexed smokeless loads on a relatively-few occasions, but my intent (and belief) in doing so was to "amplify" or "magnify" the effect of the primer, making it into a primer-on-steroids, if you will. Generally, I find that I have enough options in powders that duplexing is not needed. However, I'm not yet into wide useage of 872 or 860, either, and this is liable to change if I ever get into the slow surplus stuff.

In blackpowder, I've satisfied myself that duplexing's a viable way of greatly-reducing fouling, and extending the shooting between needed cleanings. In most competitions I'm aware of, duplex BP loading is not allowed. However, I'm not shooting competition and don't worry about the legalities.

On just one occasion, I loaded blackpowder AS THE FILLER over a smokeless charge in a .338 which was giving me fits. It functioned fine, and no fouling was noted (I guess NOT, with all that smokeless commotion coming along behind it!.) Didn't do a danged thing for the accuracy, either.

ammohead
05-28-2006, 10:16 AM
I have been watching this thread, and BruceB touched on something I have been wondering about for a long time. I use 5 gr of imr3031 under 54 gr of wc860 in my 338-06. It does boost velocity some, but it also cleans up the unburned powder kernels. What I have been wondering is...can the very slow burning powders be used as a filler for other loads. It is my experience that full cases provide better accuracy. Could I use wc860 to top of a load that has say 85% density?

This would be a compressed load so that the powders would not mix.

Bass Ackward
05-28-2006, 10:28 AM
Could I use wc860 to top of a load that has say 85% density?

This would be a compressed load so that the powders would not mix.


AH,

Sure. But just realize that your filler is going to contribute to pressure. If your load was 28,000 psi before, you may have to cut back to compensate.

But slow powder filler will contribute to bore fouling, to some degree, unlike PSB that will clean the bore of minor lead and fouling for the next shot. If you don't have a leading problem or as long as you compensate for the fouling by the lube you are using or by using a harder bullet, you should be able to find an accuracy point there somewhere.

Me, I prefer the PSB. It allows the use of softer lead at the same pressure levels and has done away with my winter lube / fouling problem. I spent 3 years playing around with lube and nothing worked well enough that my groups were the same year round. PSB has taken care of that problem too. (as long as I use slow, temperature insensisitve powders.)

lar45
06-09-2006, 05:11 PM
definition of (PSB)?

When I ordered my case of surplus powders from Bartletts, I tried to get a jug of WC860, but he was out at the moment, so I got some IMR 5010 at $3/#. (actually I think he had some 860, but was saving it for the regulars)

I think the way to go about this would be to get a pressure trace setup. Then you could see the pressure vs time of different combinations.

I still think that WC852 has something weird going on.
When I loaded it in my 06 with a 165 Rem corecokt to 2700fps I started to get pressure signs on the case and sticky bolt lift.
It's almost like it has a burn rate similar to 4227 but weighs more, as if it is a fast burning powder but has a filler in it.
In some cases looking at charge weight and velocity produced it looks like a slow powder similar to RL25.
I've read where some people say it performs similar to 4831, but it seems that I'm getting higher pressures than I should if it behaved like a canister powder.

Clear as mud?
Maybe I should save my play money and get a pressure trace setup.

BOOM BOOM
06-09-2006, 11:17 PM
HI,
I have used 5grs. of pb as a starter on top of the primer w/ 90grs ffg.
It gave the same point of inpact as 110grs of ffg in my 45 ML.
KICKED THE SAME TOO!