Great description of FOC. I made a mistake and said i was told my 2117 were too heavy....I meant too stiff and that affected accurancy.

Now this will be a dumb question but I saw brass weights that almost looked like washers that get screwed in almost along with your tip, is this what you're talking about? If not I'm assuming if I look, I'll find these type of inserts but how would one find the FOC? It sounds like the weight just goes in the front? One last question, if Im shooting a 400gr arrow, what would a good weight be after the added brass? thanks for the help