broadhead/fieldpoint flight

[skeeter@ccia.com]

I have a different flight path from my Mussy 100gr broadheads than I do my fieldpoints. Not much but enough I need to move my sights on my crossbow when making the switch. I have heard to try this.

Measure the length of bolt/arrow from tip of broadhead to end of knock....divide this in half... mark shaft at this point.

Now find the balance point of bolt/ arrow and mark this point on shaft.

Measure the distance between the 2 marks and divide that by the length of the bolt/arrow and multiply that by 100

This should give the FOC (foreward of center) %

If FOC is 10% use a lighter broadhead and if it is 7% or less, use a heavier broadhead.

Now the question...I get a 5.2% reading...could this be the reason for flight difference and if so....should I invest in say a 125gr tip instead of my 100gr?.....has anyone tried this solution? The bolts were matched by Horton when I bought the bow so I figure they knew what they were doing.....but they gave me expandables which I lost a deer with for not opening...I knew this by looking at the enter/exit of the deer I got later....so I switched to my old faithfull Muzzy mini mags....taken lots of deer with these....