I would get about 15 shots from my smr then it would build up enough to block the touchole. I always clean the oil from my rifle with alcohol but the last couple times i decided to soak a patch with alcohol and shove it down the barrel on top the breech and retrieve it with a puller after wiping the breech with it. As of now i have shot 40 shots and the gun works flawlessly with no blockage and miniml fouling in the breech area. There must have been just enough oil left on the face of the fat face breech plug to start fouling buildup from unburnt powder.