duplex loads for 38-55 WIN

[JerryW]

Anyone tried them? What smokless and how much? I Have a CPA and a Shiloh in that caliber. Thanks Jerry W

[boommer]

Sure have I use 5 grains of sr4759 or 4 grains 2400 just finished loading some up in sr4759
with either powder you'll gain about 125 TO 150 Fps and less fouling I load with Swiss 1.5 and get good grouping, the extra ignition burns that course powder in a smaller bore. Compression needs to be lite 20 thousands at most and use a card. The velocity will be up there so with a soft bullet you will want good lube and good bore fit to bullet. My load is Jammison case 2.120 length,Win large primer, .5 Lee dipper (5 GRS. sr4759) 42GRS. Swiss 1.5 by volume not weight thru a drop tube, .30 vegi card LEE 255gr bullet casting alloy 1-30, SPG Lube. I load Duplex in 45-70 and 45-90 too and and hav'nt seen any difference in using Mag primers.

[August]

Same here. I've used 4 grains of 4759 with 40 grains of Goex Cartridge and Shutzen 2F. Worked well. Lube can become a bit more critical with duplex. In other words, carry as much lube as possible.

[missionary5155]

Good evening
I have used 5 grains Unique + whatever amount of 2f it took for that boolit to give 1/4 inch compression with the boolit nose touching the lands. This is in my ballard 38-50 (38-55 brass enters).
God Bless You !

[oldhickory]

Like Missionary, I've been using a 10% ratio of smokeless to black for years in BPCRs using Unique, and it works great!

[montana_charlie]

I have a general question about choosing a smokless powder for duplexing with BP.

Is the rate of burn a real big deal in such a small percentage of the overall charge?

I see AA 5744 recommended for complete charges, along with SR 4759 and IMR 3031.
And, I suppose, any of those could be used for the 10% charge, too.

But, there are recommendations for powders such as Unique and 2400 as duplexers.

I found a fairly comprehensive comparison chart for smokeless powders at http://www.geocities.com/CapitolHill/Lobby/1221/powders.htm

On that chart, Unique is pretty fast, while 2400 is a ways down the list toward 'slower'.

SR4759 is 'real slow' compared to the first two, while AA5744 and IMR 3031 are slower yet.

All of this seems to indicate that the 'rules' are fairly relaxed when choosing a duplexing powder. I am wondering if experienced users agree with that assessment.

I have a can of SR4756 (which falls between Unique and 2400 on the rate of burn scale) which I will never use...since I no longer reload shotgun shells.
This seems like a useful choice for duplexing...if I ever decide to try that method.

If I receive credible advice that it is not a good idea, I see no reason to continue to keep the stuff around.

Any answers...or guesses?

CM

[ktw]

Any answers...or guesses?

No duplexing answers. I have all the same questions and hope someone comes along to answer them.

I also had a can of SR4756 to get rid of at one point. It worked well under a 120gr plain based plinker in my 30-30 at ~ 9-10gr

-ktw

[missionary5155]

Good afternoon
Great Question montana ?
I have not experimented with any other besides Unique for Duplex. When I started with my trapdoor Danny Powel suggested using Unique up to 10% for a cleaner burning load. Seem to work so well at about 8% (or so) that I figured it was the way to go. Plus I had 7 pounds in a jug. I have been using Unique since I loaded my first pistol cartridge. I seem to sooner or later try Unique in everything I load for. So when I got my 38-50 Ballard I reached for the Unique jug and been using it in other 38-55 (levers) duplex loads with no problems.
Have used it in 43 Spanish also and againg works great. Used it in Black powder shotshells but only at 5% kicker. So maybe that would be an interesting experiment for those summer dog days when the fish dont bite.
God Bless you !

[badgeredd]

I tried 5 grains Unique with the black in my 40-65 and I was amazed at how little fouling I had with it. The suggestion came from Black Prince. I just looked and he hasn't been on here since last August. Anybody know anything about him not being on here?

Edd

[boommer]

accuracy wise don't see any improvement over my pure black loads but the reason I Duplex is cleaner burn and velocity. Powder wise any faster to mid-range powder will work and burn rate dose not change much velocity on ten percent rule. Ive started playing with 4F duplex loads (old school) and deviation on loads in 38-55 7.2 fps on one 5 shot string avg. on 20 rounds over all was 10.8 according to my math and accuracy is there, but this was my first with these loads today. Now in the 45-70 4F duplex loads 9.0 Fps deviation over all today on 10 rounds. THAT IS GREAT deviation never seen that. Maybe a fluke I don't know. Has anybody played 4F duplex loads.

[montana_charlie]

The suggestion came from Black Prince. I just looked and he hasn't been on here since last August. Anybody know anything about him not being on here?
Just guessing...he probably decided he didn't need the unearned insults.
CM