Hmmm... not much to add to the previous suggestions. They're all on the money. Short of actually seeing you shoot the bow itself, I'd cull the "bad" arrows from your quiver and look to micro tuning. If you're arrows spin true, yet still see erratic flight, try powder testing. Was this a new or a used bow? Did the shop know what they were doing when they timed it or did the 17 year old pimply face kid with the summer job and the Fast and Furious Honda Civic parked outside put your bow in the press? Short of having a major problem, (bad riser, leaning axle, worn bushings), your bow should not be this hard to tune for the hunting heads. Check your timing and go from there... some broadheads will really fly poorly if the bow is out of time, even if the field points still group ok.