I recently completed my gunsmith training at Trinidad State Junior College and two of the classes I took had to do with stock bedding methods. One class was Benchrest Stocking & Stock Design and the other was Precision Bedding. Both classes were taught buy Speedy Gonzales who is a top authority on how these things are done. If you look him up you will see he has a shooting record that is hard to argue with.
It is my understanding from those classes that he is a big fan of using G10 rod to make his own pillars. I am pretty sure he goes through MSC to purchase the rods. I unfortunately did not have to opportunity to make my pillars in either class due to the amount of projects I was working on but from what I remember he used a simple dremel tool in the lathe to bore out the material. You can also purchase premade pillars from Brownells that I would think should work too if you do a little work to them as I think they are made to fit Remington 700’s. Just remember to cover the Lathe ways so protect them from the dust.
I do have more information in some note
somewhere and I would be happy to look for them if you’re interested in more specific info.
Here a couple links. Hope this helps!
Brownells
MSC