RE: Tuning Broadheads??
Skina is right, we need some more details. I shoot the Muzzy 100 grain 3-blade and when I first switched to them I had a similar problem, only it was to the right. Ended up being my form. I concentrated on keeping the wrist of my bow hand (hand holding the bow) straighter and with a properly tuned bow and properly spined arrow, my erratic flight problems went away. If I shoot a lot and get tired, they come back (i.e. bad form). Might want to think about that and have another experienced shooter watch you form once you get your bow tuned and are sure of your arrow spine.
Redneck