I'm not sure you can really "season" a barrel. You can leave a film of some sort,oil,bore butter,grease,ect. I have allways used BB,to protect my barrels during storage! Last year I also discovered that by using a tiny amount of BB on the sabots,they loaded easy,and actually shot better,using magnum loads (3 pellets). My friends have tried it too,and now allways lube the sabot with BB. We aren't sure if it helps the sabot survive under the extra pressure of heavy loads,or cuts down friction as it travels down the bore? What we do know is it improves loading,and accuracy. Before using the BB on the sabots,the ones recovered down range were pretty much destroyed(petals missing,powder cups ragged(bases),ect). Now the recovered sabots look as though you could use them again,but as far as the BB penetrating the metal in the bore,I don't think so. Ron