i've used moly coated bullets with no ill effects. the moly is more difficult to clean though. in my case i needed to add approx 1-2 grains more powder to achieve the same velocity, so mine at least created less pressure. as far as accuracy i can't compare my bullets to one another since i shot different grains and different brands of bullets. my moly coat bullets were barnes xlc's in 225 grain .338. they grouped exceptionally well.
hope this helps.