I have not used slip, but a friend let my try some of his tetra grease. I was amazed at the difference on a Defiant all stainless--and I have tried a lot of different lubes. Not sure what you are running your bolt it, but worth looking at. It goes on thin, but you can really feel the metals sliding a lot smoother....even on my cerecoted stuff.
It it also holds up vrey well thought a day long match.
ZY