depends on your draw length, the arrow length and what it all does to your FOC. The easton arrows website has great tables to dtermine all that stuff. A 100gr will likely be good but you should check the website.
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I don't like people who don't like dogs !
Yes it would help if we had your arrow length. Either way, I'll put in another vote for 100 grain heads.
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2006 BowTech Old Glory 70#/31 inch draw
QAD Drop Away Arrow Rest
Spot-Hogg Hunter 5 pin
6 inch Fuse Axium Stabilizer
Gold Tip Ultra Light Pro 300's
100 grain NAP SpitFire Mechanical Broadheads
Scott WildCat Release
Check out the archery programs like OnTarget2 or T.A.P.(the archery program). They have helped me out immensely and tell you exactly what you should be shooting. After using the programs I found out that I have been shooting an underspined arrow for the better part of 2 years! No wonder I could never get a bullet hole when paper tuning. Duh!