I have been using extreme pressure grease, with suspended graphite for years. I put it on the lugs, sliding rails, and cocking peice eccentric at the rear of the bolt. A little dab will do ya, and it works great. Slick and smooth!!
Because it gets somewhat cold here occasionally I use TSMoly Arctic Grade grease. Like all have posted a little goes a long ways.
I made my own gun oil/cleaner, wipe it on, then wipe it off; a little stays behind. And just a dab on the rear of the lugs. The grease has worked at all temps, once leaving an FN-FAL outside in my porch at -27* F to see if it would still run; it did.