Boring broadhead tuning question

[pseman]

Sorry to bother you all with a tuning question, but I just got some STOS 200gr broadheads and when I shot them they hit quite a bit lower than my 200gr field tips. tried 2 different heads with same results. The arrow looks like it dips about 5 or so yards after the shot and at 10-15 yards the arrows hit 4-5 inches low. They are directly below the bullseye but too low. Do I just need to adjust my nocking point down? Should that bring my point of impact up?

Thanks,
Mark

[southernarcher]

I would say yes to the nock point move.

[aromakr]

Mark:
I think we need more info from you, I don't believe moving the nock point will help if your bow is well tuned now, moving it down will cause arrow flight problems, you should have arrived at that nock point location because it gave the best arrow flight i.e. no up and down movement in flight. Changing its location would disrupt that.
 
I would bet you somehow use the end of your arrow in the aiming process! If that is so your broadheads are longer than field points which would cause you to aim lower.
If both arrows are flying well and printing inline with your point of aim its not a spine issue.
Bob

[pseman]

Bob, I don't conciously/purposely use the arrow as an aiming device. I may use it and not know it, but that is a whole other thread.

I don't notice the "dip" that I mentioned above when shooting field tips but it is quite noticeable when I shoot the STOS. Again it is only a vertical change in POI the left/right is still spot on.

Mark