In my Ruger New Vaquero’s Black Powder fouling appears to accumulate in the chambers on the sloping ramp leading into the throats.
The build up of fouling at this location prevents some chambers from seating cartridges rim down onto the cylinder face.
A high standing case head scraping along the recoil shield locks my revolvers up.
This starts at approximately shot number 30 with one chamber requiring a hard push to seat the bullet. As more shots are fired other chambers start requiring hard seating to get the case rim down to the cylinder face.
Some fouling does accumulate on the front quarter of the cylinder base pin but that hasn’t stopped cylinder rotation.
Fouling accumulation on the cylinder front has never stopped my cylinder rotation.
I am using 45 Colt Hornady brass annealed and trimmed to 1.275”.
CCI 350 primers, 35 grains of 2 fg Old Eynsford BP
My cast bullet is from Lyman mold 452664, cast with 20:1 alloy.
Bullet is lubed with homemade Emmerts Improved.
The revolver is lubed with a Jojoba based oil specifically “Lube Gard Premium Universal Lubricant”.
The above mentioned load, lube and gun oil has been working well in my Miroku built Winchester M73 24” barrel.
Would trimming my brass slightly shorter (~5 thou shorter) than the “Trim To Length” help? This will make a little more space available in front of the bullet ogive to the ramp of the chambers forcing cone.