RE: arrow sizing question (broadhead size)????????
Need some more information from you.
The Beman ICS 500's are pretty light at around 7.4 grains per inch so I assume you are shooting a lighter poundage bow and/or a short draw length. IMO, your finished arrow weight shouldn't be much lighter than 6 grains per pound of draw weight. For example, if you are shooting a 50lb bow then the total arrow weight should be around 300 grains (50 X 6 = 300) Opinions vary on this figure with most manufacturers recommending nothing lighter than 5 grains per pound of draw weight. I like 6 grains per pound.
What length of arrow will you use?
What type of cam?
If I had to make a guess, I would think a 100 grain tip would be more than enough to balance out your arrow.
The Mouse