Real turpentine is a must
Mixing natural turpentine - not any turps substitute/paint thinner/refinery leftovers - with the BLO helps it to penetrate the wood. Simply sloshing on linseed oil can result in a sealing layer of what is effectively linoleum on the surface and very little deep penetration of the wood.
And when treating a very dry stock, the internal surfaces (barrel channel and receiver cut-out) must be liberally oiled, as these areas have usually been ignored for the last century or so. Yet they are the areas that are heated up and dried out most by shooting. Don't be mean - use a narrow (1/4") paintbrush and make sure that you get the oil (made thinner with a little turpentine) into all the nooks and crannies, including the system bolt holes - and the stockbolt hole (if the rifle has an Enfield-style stockbolt)..
Make sure that the oil has really penetrated and dried before repeating any treatment. No tackiness! This means being patient and waiting a couple of WEEKS after the first soaking of the internal surfaces. Subsequent treatment can use less turpentine, but the very first must penetrate well, as later applications seal the wood more and more.
Remember, the primary object is to keep the wood healthy, not to make it look pretty. Prettiness is a by-product of decades of care and drop-by-drop polishing!