get yourself a onepiece coated cleaning rod, and clean the bbl FIRST!!!!! THEN , do a bbl break in, 1 shot, clean and lube, for 5 shots. then take 5 shots, do a clean and lube, for 5 groups. that should be enough.
for accuracy , it should be a total tack driver. if not, it may need a pressure pad up front under the bbl, or a full bbl freefloat, or a combination of both.
lastly , keep two boresnakes, or an otis cleaning kit, with 2 brushes in it;
use one snake or brush, to put cleaning fluid on it, and clean the majority of the junk out of the bbl. then the second brush, you keep it clean, but use a light oil with it. So one for cleaning, the second for a light lube. then patch it out, and keep on fireing. to clean your boresnakes after a couple of range sessions, throw them in a nice , thick sock, then throw in the wash machine.