Back in the 90's there were companies that properly Moly coated the bore of your rifle which was the advice given at the time if you wanted to use Moly coated bullets for whatever reason. The problem with just using Moly bullets was that they left a residue in the bore which could affect accuracy by causing slight inconsistencies as it was not an even coating and could not be completely removed during normal cleaning so you would get buildups of the stuff in patches. I remember when the fad started as I was a benchrest shooter at the time and it didn't take long for us to realise it was not as good as all the hype had led us to believe, in fact, when I collected a new bench gun from Dave Tooley he advised me not to use the stuff. IMO I can't see any benefits from using it.