That's funny, "BLO" just didn't translate in my mind for some reason. I've never really liked it, does not seem to really keep moisture out of wood, and kind of has a gummy feel. Never seemed to have "staying" power and seems, to me, to rub off easily if the rifle is getting carried in the rain. I've never tried cutting it with spirits or anything else, that may make a big difference.
I've never tried raw linseed on metal, sounds good for the axes and things I carry in the Power Wagon.
On gunstocks I like to rub them down, repeatedly over weeks with something like a walnut oil, or mink oil, maybe olive oil, and let that dry and soak in, and then go to a tung oil or Danish oil/stain, and do many applications of that. Eventually when I think that has "taken", I might dilute some Minwax "Tung oil Finish", which has no tung oil in it but is a poly-product, and rub in a very light coating of that. Not "put it on", but rub it in. Also have a bottle that is a mix of a very small amount of "Tru-Oil", which is not true at all and is another poly-product, and a mix of other oils and stains of which I don't remember, but same thing, rub that in, especially a couple of weeks before a hunt, and the gun will keep the hand-rubbed oil finish look, but be quite water proof.
Having said all that, there is an interesting formula we use on wood Inuit/Greenland kayak paddles, I forget but it uses Pine tar and turpentine, and something else. I wonder how it would work on a gunstock. ? It is certainly tough and waterproof on the paddles.