BG,
I took my new arrows out today and shot them at the target with field points just to see what they would do. I am just borrowing the this bow for the season and when i picked it up the guy had some carbon arrows that i used to test the bow. When i shot them into my target the went in to the fletchings from 10 yards. With the aluminum arrows they still had 6 inches of arrow before the fletching. My theory is that it is due to the aluminum arrows being quite a bit thicker (3/8") compared to the carbons. My target is just a cheap foam 20 dollar one from walmart.