I like circa 1850 Tung Oil now, for a stock finish.
In the past I've had good performance with Spar Varnish
and True Oil, with both giving long lasting finishes.
The Spar Varnish is about as water proof as you can get, but it stays tacky a long time. Drying
time is long, with the requisite to keep the stock isolated from dust.
Thus, the compromise is Tung Oil.