Powder Prevents
Another boon was the development of powders with anti-copper fouling technology. Hodgdon has its CFE (copper fouling eraser) series which includes the CFE 223 powder. Several of the Alliant RL series powders incorporate technology to reduce copper fouling, as do the IMR Enduron series. This technology really works. It is particularly useful in rifles shot a lot, or with ultra-high velocity cartridges.
Another way of reducing copper fouling is by coating bullets and/or rifle bores. Molybdenum sulfide (Moly) bullet coating got a lot of press a decade or so ago. Unfortunately much of the coverage focused on potential velocity gains instead of the real advantage, which is being able to shoot more with less fouling. Since most rifles don’t actually get shot very much, many shooters gave moly a try, found their lives pretty much unchanged and decided it was a waste of time.
Today there are other coatings such as Tungsten Disulfide and Hexagonal Boron Nitride that some feel are superior to Moly. Personally I use coated bullets only in rifles I shoot a lot, as in 1,000 rounds or so annually. For the typical hunting rifle which might get fired 20 or 50 times a year. it hardly matters.