Black powder duplex loads?

[swheeler]

Well I really don't need ALL the holes to touch; maybe only 4 like here from 1000 yds.!


10shots by Sharps45 2 7/8, on Flickr

Very good sir!

[RMulhern]

And I would add that any rifle....in most competitions that could hold 1 1/2 to 2.0 MOA would win....most events!

[swheeler]

RMulhern

You're confusing 45 2.1 with facts.....how can he do his "I'm the master, you're the grasshopper" routine when you post shooting like that

Larry Gibson

You funny guy GI

[Chill Wills]

And I would add that any rifle....in most competitions that could hold 1 1/2 to 2.0 MOA would win....most events!

I would add that in most Creedmoor competitions, just keeping all your shots on the paper for two days will place you high and you keeping then all in the black would win. Groups like yours are shot in the calm. Rarely are match conditions so friendly.

[RMulhern]

I would add that in most Creedmoor competitions, just keeping all your shots on the paper for two days will place you high and you keeping then all in the black would win. Groups like yours are shot in the calm. Rarely are match conditions so friendly.

Chill Wills

So true! I've shot on several occasions at Raton in the Palma events and yes....the winds do blow!! And change directions quite regularly!!

[Oyeboten]

I was experimenting with Duplex Loads for .38 Special.

I had to leave off before I was through the methodical sequence, but, it was so far so good anyway.

Straight BP was providing a nice even series of FPSs ( same Bullet in each ) with three different Barrel lengths.

The sequence of Duplex Charges likewise, showed entirely perfect graduated increases in Velocity according to the proportion.

Proportion of Smokeless ( 'UNIQUE' ) I was using ranged from 1 to 5 percent by weight.

I forget now the figures, but each 1 percent increas in Smokeless showed a steady and even co-responding increase in FPS.

BP was 3 F 'Goex'.

Powders were mixed together for a uniform distribution of the Smokeless.

[BPCR Bill]

Hang Fire, yes I shoot duplex BP reloads but a little history first: The match shooters around the turn of the century used a different 'smokeless' powder as we know it today. That 'smokeless' powder was Dupont's Lesmok and Kings Powder which both were semi smokeless powder with charcoal mixed with nitrocellulose , sulfur and potassium nitrate.
This duplex's purpose was to increase the velocity for reloads used in matches, specifically 200yd Schuetzen matches. These shooters also used straight semi smokeless rounds
Later on, real smokeless came into being such as Lightning that was pure nitrocellulose based and the use of duplex and semi smokeless rounds waned going up into the 1930's. Remington factory semi smokeless Lesmok ceased around pre- WWII. Kings semi smokeless in the early 1930's IIRC. I have a box of Remington 22lr rounds that have a 1939 birth date

OK, as for duplexing the rule is: use a smokeless powder that by its self does not generate a pressure for a given charge & bullet weight greater than the SAMMI MAXIMUM pressure for that caliber using straight black powder. Then use 5 -10% smokeless of the black powder charge and reduce the black powder by that 5-10% ... dependent on the smokeless powder psi or CUP

The warning caveat: Duplexing with real smokeless powder on the market today is not recommended for any reloader unless they have substantial smokeless powder internal ballistics knowledge for the powder that is intended to be used

I am aware of a Pedersoli 45 2 7/8" 74 Sharps that was destroyed with a duplex load of 12 grains Red Dot and 2F Goex. The block held, but the barrel and reciever ring, along with the forearm, were blown all the way to East Jesus. A miracle that the shooter only had some wood splinters in his forearm.

Regards,
Bill

[Oyeboten]

Hi Bill,


You relay -

I am aware of a Pedersoli 45 2 7/8" 74 Sharps that was destroyed with a duplex load of 12 grains Red Dot and 2F Goex. The block held, but the barrel and reciever ring, along with the forearm, were blown all the way to East Jesus. A miracle that the shooter only had some wood splinters in his forearm.

Misadventure of course may occur when an operative makes errors in loading with Smokeless alone, and, we have all seen images or in some cases, first hand examples, of Guns which were damaged or burst in various ways.


With any Duplex, one would do well to bear in mind the percentage of Gas or elastic pressure as matters evolve, which each Powder is liable to generate individually, and, for these, when combined, to remain within sensible limits for the Arm in question, of course!


I imaging the poor Pedersoli, with the charge described, was given quite a ways over a 'Proof Load', and, obviously, it did not like it.

[bigted]

so the question i am most interested in has withered n dried up...which is of course...when using straight bp for the charge...what was the outcome when using a charge of 4f powder for the duplex and the remaining charge being 2f or 1f bp? id do thid experiment...and prolly will someday...but ill have to send off for a can of 4f powder specifically for this experiment as i dont use 4f in anything else in my current stock of guns

this would interest me in that it would remain 100% blackpowder but maybe with a cleaner burn???

DO TELL PLEASE

seems like we get the posturing and pee contests that confudiates the question at hand...still n all it is a hoot to read as long as im not the one in the middle...ha....oh n happy x-mas eberbuddy

[ss40_70]

bigted
i tried duplexing 10 grains 4fg goex under 60 ffg in my 45-70 about 10 years ago
i didnt exactly try enough to say i had conclusive results but in the 50 rounds i tried fouling wasnt any less then a strieght ffg load and went from a dry fouling to a hard / crusty fouling
acuracy was a toss up it didnt shoot nearly as good groups as my normal loads do but then i could have been having a bad day shooting .. i never tried again to see

[Chill Wills]

Chill Wills

So true! I've shot on several occasions at Raton in the Palma events and yes....the winds do blow!! And change directions quite regularly!!

Rick, I reread the last post I made and I can see how you might have been offended. I won’t try to explain what my comment was intended to be, I rather express that I wish I had not written it in haste. Forums lack face to face and sometimes poor writing offends. I was not my intent to offend you, Sorry! No matter what, I always try to preserve everyone’s dignity.

Merry Christmas

[Chill Wills]

Ted, this is by no means the final word on BP with BP duplexing. I have and a number of my skilled BPCR friends have worked the 4F under the 1F kind of duplex and a lot of variations. No luck improving on one grade of black gunpowder. The better the brand helps a lot for sure. I hope you have some luck and fun trying it. Let me know.

Writings from history suggest the old dead guys came to the same end. A bit of smokeless makes a big difference.

SR-4759 IMR-3031 R-7 Powders in this class work well. Even very small charges work to clean up a load.

[blackpowder man]

I shoot duplex loads using a small charge of 4759 under goex ffg. I use it for target shooting and hunting in .38-55 and .45-70 and it doesn't require me to wipe or blow tube. I shoot as many as I want and clean when I'm done. It is very accurate at the ranges that I have used it. It has not worked for me in .45 revolvers mainly because I don't have a mold for a boolit that holds enough lube. I would like to find time to make some BPCR matches and for those it would require wiping and blowing like everyone else.

[kokomokid]

Makes you think a magnum primer might burn cleaner than a muffled pistol primer?

[Litl Red 3991]

I am aware of a Pedersoli 45 2 7/8" 74 Sharps that was destroyed with a duplex load of 12 grains Red Dot and 2F Goex. The block held, but the barrel and reciever ring, along with the forearm, were blown all the way to East Jesus. A miracle that the shooter only had some wood splinters in his forearm.

Regards,
Bill

Jezus, am I the only one who shivered when seeing "12gr of Red Dot" ???

[Sharpsman]

If you study the history your trying to duplicate. You would find that the early leaders of long range accuracy actually tried and used triplex loads of different granulations of blackpowder. All of them used new technology to increase accuracy and ease of shooting. None of them went backwards................

Yes....BUT NOT SP!!

[bigted]

according to a few articles from yesteryear ... and ... a couple old vintage Lyman loading manuals ... yes "Smokeless Powder" for the duplex

... ... ... ... ...

[kens]

I have used various duplex black powder loads.
Most common is a partial charge of FFFFg in the breech (for easier ignition) and the balance of the load FFFg. This was for long rifle hunting applications.
I also used holy black as a cartridge filler when loading reduced loads in large capacity cases. An example of this is a reduced load of Rel7 with a filler of FFFg to fill the case, in a .375 H&H.