As deep as you're in this little darling (oozing sarcasm) , maybe a new Green Mountain bbl installed by a master would have you money ahead ( casual suggestion) .
I know a guy in Arkansas that does a little lever gun work . His personal 1886 Win in 45-70 shoots 2.5 MOA to at least 300 yd .
I sent him a Carcano and he sent me back a sub MOA wildcat for paper patch in 7x6.8 which proves miracles happen every day . He's a great guy to do business with also .