On blued steel I will use a light grease between base and action... it prevents rust in that area.
Do you mean sealant as in bedding the bases to the action? If that's what you mean, I only do this if the bases are not a great fit or screws are coming loose all the time. I use jb weld but devcon would probably work better.
Any specific grease you use?
On blued steel I will use a light grease between base and action... it prevents rust in that area.