mustad
Do you use a breech plug grease? What kind of grease is it?
Way back when.... when I tried to use grease I stained the heck out of the throat of the bore with burnt and driven in grease. The grease is super heated and forced into the pores of the metal of the throat. It took several cleanings over a period of timeto get the bore back to the shiny bore that I wanted. Since this - I do not use BP grease at all.
spaniel
T7 pellets do have that ring of real BP around them... there is no up or down side to them.