+1 on what was said.
My only tip on greasing is to go to Lowes and get yourself a big ol' tube of white lithium grease for $1.29 and then look for some of the glue syringes that they have as well. The syringe does a great job for being able to accurately apply small amounts of grease. I have three loaded up with grease, each having the syringe tip cut at a different length so I have different hole sizes for more or less grease application. Its worked well for me and may be worth trying.
However, please do keep them greased or at least oiled. The last time I was out I wound up helping out some guy who kept blowing the op-rod on his garand out of the track. Not only was he shooting commercial hunting ammo (which probably was the problem) but the rifle was BONE DRY... It made me want to cry. In fact, I could hear John Garand crying... So, please, grease or oil. Your rifle will appreciate.