I never carried the M-14, except in boot camp. I found it a fine weapon that would fire under almost any circumstances.
But I do have great faith in the opinions (and experiences) of my friends. If you say that the use of linseed oil would reduce the tendency to warp, I accept your recommendation as truth. But I also know that neither Pat (who served in the 9th Infantry Division) nor Tony (who served in the 25th) would not make such a statement unless they believed it to be true. Neither has any need to lie or misstate after all these years. Pat did say that M-14 would have been a fine rifle for Korea or the Fulda Gap, but not for the heat, humidity, and muck of the Mekong Delta.
I would love to talk to Pat and Tony (mainly because I just enjoy talking to fellow vets) but I guess I'd ask them "what wood stock warping problems did we have with M-1s? M-1 Carbines? Springfield '03s and Krags and Lee-Navy's and M1884s?"
The M-14 stock wasn't in any way different from those rifles as far as thickness or material or shape goes - and they all were used in hot, humid environments.
I think that some of our guys have to think up problems with the M-14 to explain or justify the mess that was the M-16.
The '14 was reliable, accurate and extremely effective. It was longer and heavier than later rifles and if you had the thing slung when you entered a GP tent, the bayonet lug would always catch on the cable above the entry and it'd yank you off your feet ("carrier qualifications")- but if your life depended on having a rifle that killed effectively at 10 meters to 500 meters and always fired when you wanted it to, that was the rifle to have.