Forgot to update on this. The powder coated 405 HB bullets I cast using a 20 parts lead to 1 part tin from the Lee mold using smokeless powder and no lube worked very well in my Trapdoor. Accuracy was good and no lead.
I used the the same powder coated bullet and pan lubed them with a 50/50 beeswax olive oil mixture over 60 grains of Goex.
Accuracy was really good in fact better than the 4198 I used.
Shot 15 of them with no blow tube or wiping and had no issues with fouling. There was a small star of lube at the end of the muzzle.
First two water damp patches were black with soft fouling and a few more the barrel was shiny clean.
Most important thing to me was zero lead in the barrel to clean out.
Powder coating and lubing bullets may not be for everyone but it was a complete success for me.