445 Supermag,

If your strictly into deer hunting I would forget about the Steelforce alltogether. With your numbers you are putting out about 80 lbs of KE which is plenty for just about any mechanical head on the market. If you really want to shoot fixed blades I would go with a smaller profile 3 blade like a Wasp Hammer SST or Muzzy which would probably fly a little better than the Steelforce(at that speed). If you have your heart set on Steelforce I would increase your arrow weight.

I also ran your arrow through the FOC calculator and you are at roughly 10%. I myself shoot at about 13.5% for my 125 grain broadhead. If you used a 125 gr broadhead it would bring it up to around 12% FOC and also slow your speed a little. But if you are under spined already this could make it worse.

If you goto the easton website they have a EXCELLENT tuning guide there.

http://www.eastonarchery.com/tech_room/

Good Luck. Let us know how u make out...