It seems to be rifle specific; some make it some don't. My Omega is a prime example of one that makes it real bad. I feel fortunate for those that can use 777 as it is more available than others like APP, Pinnacle, and Black Mag'3 although those last three are ascorbic acid based and in a slightly different catagory. I like the lack of fouling of the ascorbic acid based powders and the lack of corrosion on steel. They also seem to have gained in consistency especially in the fff grade (which is why I believe Black Mag'3 is only available as fff). It works just great in my Omega.