rafsob
Hey Sabotloader, I was surprised about the crud rings with the T7. I was always told it burned a lot cleaner then the rest. I am thinking that because of the new breech plug design, it may be throwing all the gases forward so effectively that it is creating the rings. Not an engineer, but that is the only thing I can think of. I did notice a thick buildup of carbon on the B/P face in the barrel section
For most of the length of the barrel it does burn cleaner.. it is that burn zone right under the sabot where the ring normally builds up. Some people say the temperature of the primer makes a big difference.
It is normal for the face of the BP to build a pretty decent amount of crud on it - but it really does not effect your shooting. I am not sure it is carbon because it washes right off with water.