duplex loading

[bigted]

can anybody explain to me what is so bad or frowned upon with the practicing of duplex loads using smokless powder along with blackpowder? im finding them very clean and so far in my short little winter range they appear to have promise in the accuracy dept...this in a marlin SBL model 45-70.

thanks

[TXGunNut]

can anybody explain to me what is so bad or frowned upon with the practicing of duplex loads using smokless powder along with blackpowder? im finding them very clean and so far in my short little winter range they appear to have promise in the accuracy dept...this in a marlin SBL model 45-70.

thanks


Haven't tried duplex but have researched them a bit. Seems it's a purist vs practicalist debate. Both sides have their merits. My biggest question is when the smoke clears, are you cleaning a BP or SP rifle? I'm thinking BP, don't really know. Duplex loads are prohibited in BPCR comps IIRC and mebbe some classes of SASS but some folks, including me, feel BP is all that's needed for BP cartridges. Pope and Keith did a fair bit of duplex research but I haven't made a serious study of their findings. I think duplex loads may give a "best of both worlds" result but I love BP, tolerate SP but duplex just doesn't appeal to me @ the moment. Have heard rumors about safety concerns but nothing solid, yet. Wonder if you'd get better answers in the Black Powder Cartridge forum?
Sorry about the long-winded non-answer.:bigsmyl2:

[bigted]

i thought that was a good answer. i do in fact have the question posted in several places but yours so far has the most meaningfull answers yet.

in compition it makes sence that the use of pure is advisable. also in the hunting fields of the lower 48 black in pure form is understandable but here in the last frontier where the possibility of being hunted rather then the hunter is an everyday possibility everytime you make a sojourn into the thick stuff. some of these interior grizzlys are just plain mean and hungry at all times they are awake and have been known to swipe a feller off his snow machine or 4-wheeler as you go past where the bear is catched up guarding a pile of stinky meat.

hense the search for a blackpowder load that can be imediatly reloaded for action...kinda like the lyman 457643 boolit that i sized down to .452 and patched back up to .4585 and crimped and loaded a total of 54 grains blackpowder in with 6 grains 3031 and it shoots so clean it is doubtfull that straight 3031 would or is any cleaner....and i still get the obturation of shooting blackpowder....the cleanup is just the same as pure black with 2 spit patchs followed with a dry then an oily patch and up on the wa;ll again...clean as a whistle.

[Boerrancher]

I do understand your concerns about a reliable load, but BP seems to me to be more consistent under various temperature extremes than many of the smokeless powders because of the lower ignition temp. Also when shooting black, if you have trouble with fouling, to the point where the gun is no longer reliable after just a few shots, there is something wrong with your load. I can shoot my 45-70 all day long with out having to do any swabbing. I use a lanolin lube and it keeps everything nice and clean. I also run a full 70 grains of 3FG on a 405 gr boolit. It shoots 2 inches at 100 yards with the iron sites for 5 shots, and after 20 rounds, I spray the gun down with moose milk, run a moose milk patch through it, a couple of times, and it is done. The same goes with my Mod 66 clone in 44WCF. I have shot 100 rounds through it in one setting with black powder and not had a feeding or major fouling issue to the point where it degraded the accuracy to the point it was noticeable while shooting off hand. Still minute of pop can at 50 yards.

Best wishes,

Joe

[Guesser]

I've used the process in 45-70, 45-90 and have found the cleanup much easier, that was the single advantage that jumped out at me. There may be others, haven't done enough to really know yet, oh, and I sold the 45-90 so I'll be working with 45-70 for a while. Watching and listening!!!

[beagle]

Duplex loads have been around for a long time. Many with holy black have been used safley over the years by many people and they swear by them.

It's just like riding a motorcycle. When you think you have it down and are doing great, something happens to really upset your apple cart. That's why I don't mess with duplex loads.....or motorcycles.

There are many variables to duplex and yes, even triplex loading. Many of the old big bore guys started with a small charge of Bullseye, then a slower burner and topped off with all the milsurp 4831 you could stomp in a belted case. Black and the original 4831 milsurp powder started this duplex business.

Then, there are the primer guys. John Buhmiller had ignition problems with 4831 and he was shooting steel cased .45 ACP cases filled with lead and turned on a lathe as "solids" in Africa on elephant cropping. One of his solutions was to use a light Bullseye load, drop an extra magnum primer in the bottom of the case with the Bullseye and stomp all the 4831 in the case that he could and it worked well for him.

Even old Elmer tinkered with it a while before he came on the plan of igniting the powder from the front end using a primer extension tube.

A friend was loading black in a .45/70 and he fooled with it. He also put black in a .50 ammo can and used dessicant bags to suck the moisture out until he was running 20% humidity. Velocity really went up then. His next trick was to put kitchen match heads in his ammo can and drop a couple in the bottom of the case. Again, velocity went up and probably pressure as well.

I'm not saying that duplex loads are bad. Used properly, they probably have many uses. Most have been used with black and many with the slower milsurp powders intended for 20mm cannons.

The problem is, duplex loads are like nuclear chain reactions. In the right combinations, you might get something started pressure wise that you don't want. Herein lies the problem with duplex loads. MHO./beagle

[Larry Gibson]

can anybody explain to me what is so bad or frowned upon with the practicing of duplex loads using smokless powder along with blackpowder? im finding them very clean and so far in my short little winter range they appear to have promise in the accuracy dept...this in a marlin SBL model 45-70.

thanks

I find absolutely nothing wrong with it if done correctly. Purest BP shooters frown heavily on it though. Seems when it was legal for some matches the "gamesmen" (present in every type of shooting) were using only enough BP to make a little smoke. I much prefer a good cigar to sucking on a blow tube (yuckkkk!!!!!):-P

I have excellent results with my 45-70 and 45-55 loads for my TDs using duplex loads. I use 4759 and GOEX Cartridge and replicate service ballistics with the Lee 405 HB bullet. I can, and have, shoot over 100 shots without cleaning or using a blow tube with accuracy of the last rounds being very bit as good (excellent accuracy actually) as the 1st rounds. Yes, I also have good straight BP loads but with the duplex loads i don't have to clean a fouled bore after 15 -20 shots and I don't have to suck on that blow tube..........:groner:

Larry Gibson

[w30wcf]

There is pressure data on duplex loads for the 45-70 in the Lyman Cast Bullet Handbook 3rd Edition (might be in the 4th as well?).

As has been said, with the correct combination there will be no problem.

w30wcf