Yeah,you would need to be shooting 308fps with a 570gr arrow to achieve 120 ft lbs.I was going to ask you about your speed until I read the other posts.

When you get your speed you can go to jacksons archery and use the KE calculator.

www.bowjackson.com

Anybody want to place bets on his actual speed?I would guess around 280,..Are you sure you mean a 570gr axis?[&:]I mean it would take a 32.5" axis 300(the longest length,and biggest sized shaft they make),and a 175gr tip to make an axis arrow weigh 570gr.[8D]

There is also an Arrow weight calculator there with axis figures.Hope I helped.

Sorry for the excessive use of smilies,but I wanted to show a friendly post,and didn't want you to think I was giving you a hard time.