Collectors look at stocks and want to see the original type finish. For many this means BLO. Tung and Shellac are two other finishes, but it depends on what rifle you have.
BLO with a follow up of Tom's gunstock wax looks really nice.
78 year old Brit wood, original as in never stripped, just fresh coats of BLO and Tom's.
80 year old Brit wood that was stripped then fresh BLO finish applied.