I've had a life long interest in firearms but until recently was limited to reading and machine shop work.  A couple of years ago, I joined a local gun club and added shooting to my gun related activities. The club has many experienced shooters, who have been extremely helpful guides for range safety, reloading and shooting.
I've recently begun to shoot with breech seated bullets. With the 32-40 cartridge, I had no trouble chambering the case, without spilling any powder but with the 25-20 SS, it became obvious that I needed some way to keep the powder in the case. I adopted the procedure used by most of our club members, which was to use a 1/4” piece of floral foam pushed tight over the powder.
In his book “Modern Schuetzen Rife” Charlie Dell describes his experiments on ringing rifle barrels. These experiments were carried out as fixed ammunition with a 38-55 case, 249 grain lead bullet and 10 grains of Bullseye powder. He writes that“ in all cases when the powder was held back against the inside of the cartridge head we developed a ring”. In another experiment with the same load but without any wad, a chamber ring could be formed by firing in the verticle position but not by firing straight down.
Charlie Dell concludes this chapter by stating that he intends to perform the experiments with breech seated bullets and to publish his findings in the ASSRA Journal.

My questions to the forum members:
Did Charlie Dell ever complete his breech seated experiments and if so, were they ever published?
Would any of our members care to share their breech seat loading procedures?

Thanks,
Otto

I slice the green floral foam into strips about 3/32” thick x 1” wide. I use these for all my breech-seating. NONE of my charges come even close to filling the case. Foam is placed over case mouth and pushed down with the thumb. Powder slump is automatic as the case is loaded horizontally.

I've never used anything over powder, but I've not breech seated any small cases where powder might fall out either.

Smoke wrote on Nov 22^nd, 2024 at 8:39pm:


The powder, which doesn't fill the case, slumps down to the bottom of the case. 

The surface burning of the powder generates a pressure wave that travels outward from the surface toward the base of the bullet.   

In the case of pushing a wad or foam down onto the powder, the powder can't slump, and the wave from the front of the flat face of the powder (as held there by the wad) hits the base of the bullet all at the same time.  This creates a compression wave in the compressible gases, and causes a localized very high pressure that exceeds the steel strength of the barrel, causing a ring.

In the case of the wad not being on the powder, the pressure wave starts different distances from the bullet base, so reaches the bullet base at different times, and doesn't create a ring of high pressure.   

Floral foam is one of those things that acts somewhat like a more solid filler in some ways, so it doesn't ring chambers as reliably as a hard thin wad does.  But, it has been proven to ring chambers, at least part of the time.  Best to just hold it off the powder a significant amount, and don't take chances.   

Dell reported that a wad placed .100" above the powder produced a smaller ring than when it was placed on the powder. However, a wad placed .200" above the powder produced no ring.
I can see accurate initial placement of a wad at or above .200" but insuring that it stays there is problematic. 
Is there any down side to keeping the floral foam in the case neck?

Never place wads directly down on the powder.

An Alberta Schuetzen Guild shooter ringed his barrel just in front of the leade and under the base of his breech seated bullet using floral foam directly down on the powder.

I have been very successful shooting with foam wads acting as a cork in the mouth of my cases.

Finely machined Miller deHaas actions lock up real bad when you spill powder into them.

Charlie Dell also said the ringing can also be attributed to firing the case with the wad on the powder in an elevated position.

Normally we shoot OH and bench with our barrels in a level position.

The fellow who ringed his barrel was shooting uphill at the Stars and Stripes Range.

I spent a lot of time with Charlie in his last active shooting years. Most of his shooting in those days was with a Pergrine chambered in 32/357 (similar to the 32 Miller short).  What he finally settled on was a thin cork wad seated about .125-.200” or so off of the powder (to allow it to slump) then a card wad cut from orange juice cartons in the very mouth of the case.  He never explained the benefit of the second wad and I got lazy and just used the cork wad in my 32/357 with no apparent ill effects.  OTOH, Chuck Blender just used a thin wad of floral foam in mouth of his 32-40.  All of these were breech seated loads in case you’re wondering. 
Froggie

We have been discussing breech seating using smokeless powder resulting in ringing of the barrel when a wad is put directly down on the powder column.

Black Powder is a different animal requiring the case to be completely filled.