I just finished doing the FF kit on my .300rum and my .270. I thought I had shot the barrel out on the .300 rum, but the kit restored its accuracy. The kit performed exactly as described. My groups were in the 1/2" range, and then it moved to the 1 1/2" range after about 400 rounds down the tube. I could feel the throat was very rough when trying to clean the gun, and I could feel tight spots in the barrel. After the kit, it feels very smooth from chamber to muzzle, and it cleans out in less than 10 min with Boretech Eliminator. My groups are also in the 3/8"-1/2" range again. Now the .270 on the other hand performed different. It was about a 1" group gun from the beginning and was somewhat easy to clean. After the Tubbs kit, it turned into a 1/2" grouping gun, but it is now a copper mine. After 20 shots, about 6" of the muzzle is solid copper that is very hard to clean out. I can feel that the roughness is still there in the barrel. It even feels rougher than before I used the Tubbs kit. What could have happened here? I followed the instruction to the T, just like in my .300rum.