If they are close, than you probably just need a slight tweak to your rest to get them to be dead on. Basically you move your rest in very small increments toward your field point group (ie. if your fp's are hitting left of your bh's, then move your rest to the left). It shouldn't take much to get them to hit together. Both groups will move on you, but the broadhead group should move MORE than the fieldpoint group and overlap at some point. Then you resight in and you never have to worry about changing your sight for broadheads again! Mark where your rest is now so you can always go back to it if you have to.

If this doesn't work, I would just sight in for broadheads a couple of weeks before hunting season.

Good luck!! ... Shockwave