I'm new at reloading in general, therefore I'm trying to learn as much as possible before I actually start. I have some data sheets for reloads of 10 gauge shot shells that use the abbreviations "NC", "MR" and "FBS". With the possible exception of "NC" I really haven't found anything that matches the other two. I know they are talking about fillers, but would like to know exactly what they stand for.
After the laughing could someone kindly enlighten me. Thanks in advance for any help anyone will give me.