It's a glossy stock, right?
So, you're maintaining a varnish.
In that case, any furniture product designed for a gloss finish, like Pledge, would be good.
Linseed oil is my choice for stocks, like old military rifles, that came oiled. I use a 50/50 mix of real turpentine and boiled linseed oil to clean and preserve those stocks.
One odd exception, my Swiss K-31. The Swiss has an unusual mixture of 30 % Turpentine, 30 % Linseed oil, 30 % Fruit (wine) vinegar and 10 % Bees wax.
For that rifle, I use that finish to keep it in shape.
But for a simple, varnish finish, use a furniture product. It's designed for varnish.