I think that some of the early smaller bore (sub .35 bore cartridges)  BP shooters have used a duplex charge,  thats why ideal/Lyman made that 2 chamber measure.  I believe that the 2 or 3 grains of the "starter" powder helps get the fire going quicker and hotter so that the main charge burns more completely and gives less fouling. Of course the more gentlemanly pace of most schuetzen matches allowed time to clean guns, and have a sandwich and a beer between shots

I've never heard that explanation before on the ideal #6.  In Pope's pamphlet he says the reverse.  He was talking about his own powder measure of course!!

Wouldn't it be correct either way on the #6? All that makes it throw one or the other powders first is which side you put that powder into.

I have also seen loads that used a small amount 5 or 6 grains of black under a charge of early smokeless. Early primers were designed to set off black powder and often gave indifferent results with early smokeless. 
Our primers of today are much stronger than the old primers. That is why you will see occasionally a load that calls for a priming charge of Black.

40 Rod

In one of the most recent versions of the SPG BP loading primer there is some space devoted to the 32-40 using BP. Might want to look that over. 

I have done a bit of duplexing for 45-100 and 45-110 using PPBs. Worked well to virtually eliminate fouling so I was able to sometimes shoot 20 rds accurately without wiping. Most BPCR shooters though consider it sacrilege to do so.

As to ringing a chamber, I have heard that any wad may be cause for ringing a chamber in the large cases BP using smokeless since they can shift around. Once I inadvertently loaded some 50-70 using smokelesss and wads. When I realized it later I took them all apart just to be on the safe side.

Using straight Swiss 1.5F I can shoot 10rds of 50-70 without blowing or wiping. Using Goex/Schuetzen though is a problem. FWIW if you look closely at the Schuetzen label you will see it is made by Wano in Germany. Wano is considered the lowest of the low in Europe and only used for cannons and signal guns.

SS

Here at Jefferson State Schuetzen Society in Oregon. We started a match about 3 shoots ago that allow duplex BP loads. It is traditional and can be fun. Your club just has to put a match in the schedule and that's is all it takes. ASSRA's BP rules still allow 15% smokeless.

Back when we had two ASSRA clubs here in Oregon, we had about four matches a year that had duplex BP matches. Plus, there used to be a muzzle loading club called Western States that had a cartridge, duplex match.

Frank

Yes, John. Tony and Dave and I are calling to you to come up

4th Sat, March to Oct.

Frank

Wow! Didn't think that I'd start all this with a question about ringing a chamber, but happy that it did. I like listening to all of you and learning more. 
  Monday I did some plinking with the Stevens 44 in 32-40. Had a batch of Lyman 319247 bullets that were slightly flawed and thought they would be just fine to do some plinking with. Loaded them in un-sized cases over 12.5 grains of IMR4227 and a standard Federal 210 primer. One of the things that I like about the Stevens 44 is the way the breach block rotates into position when the breach is closed. It cames the cartridge into the chamber. With the bullets finger seated long in the case they are seated deeper into the case as they make contact with the lead ramps to the rifling. The ammo that I have assembled using this method shoots very well. It's not as accurate as breach seating but as a form of fixed ammo its is A-OK. There were 24 rounds of ammo loaded and shot Monday while plinking at ranges from 25 yards to 200 yards, and I was delighted to see how well the load and rifle shot. Small steel targets the size of a pack of cigarettes were used at different distances. I'd switch form one range to another using the pre-recorded elevation settings that I have established for this loading. By the way my 44 it topped with a 12X Unertl 1.5" scope. That makes the serious testing and hitting small targets a bunch easier for me. 
   Again I want to say thanks to all of you that have responded to my questions. You are a big help and I enjoy learning for all of you.    Sendaro