Triple Se7en powder creates a crud ring which is a type of barrel fowling, when you use it. The major area is where the powder meets the projectile. You are more likely to get a crud ring when loading high charges. If you load 100 grains of it and shoot a couple times, you will feel it when you swab. The good thing is if you swab between shots the build up is easy to remove and you will not notice it all that much. The other good thing is simple water will remove it. If you have not noticed a crud ring, then your lucky. All propellants will create a crud ring. Some of the fowling is much harder depending on the type of powder you shoot.