Broadhead tuning - at my wit's end!

[Sika]

This one has me and my pro shop stumped.

Set up is Hoyt Defiant - 26.5" draw @ 46 lbs.
Arrows are Gold Tip XT Hunter 400 spine (I've tried 500 also) cut to 26.5"
100 grain field point with 50 grain weighted insert. Total arrow weight is 375 grains. Rest is QAD drop a way.
Broadheads are 100 grain slick tricks.

At 30 yards, my broadheads are consistently impacting 6" low relative to field points. At 20 yards, still low but only by a couple inches.
I have tried moving the rest up. No change. I have gone from 500 to 400 spine arrows...no change. I have tried different broadheads..even worse.

Now I'm seeing what appears to be color transfer from my vanes in the "U" of the rest.

I'm at the point of wanting to start completely over with a different arrow rest. I've had QADs before on other bows and have never had this problem. The pro shop recently checked cam timing. Arrows made good tears through paper. I haven't re-checked paper tuning since I messed with the rest.

Outta ideas...what say you green screen?

[jake-1024]

Sounds like the rest isn’t dropping fast enough if your vanes are hitting it. What vanes are you using?

[TxAg]

Have you changed the nock height?

[BLACKFINTURKEY]

Have you tried indexing broadheads to your vanes? After perfect paper tuning my bow still wouldn't shoot viper tricks with field points, once I indexed them with the rubber o ring they had perfect flight. My pro shop told me to index them vertically however they still wouldn't fly properly I had to rotate them on a horizontal plane for proper flight. Now once I find the proper index on my BHs I can get viper tricks,Magnus 2 and 4 blade, Magnus black hornet, and a few others to fly perfectly with field points. It's worth a shot.

[Sika]

Sounds like the rest isn’t dropping fast enough if your vanes are hitting it. What vanes are you using?

The little raptor vanes that come on the GT's.

I agree, that could be a problem...but why would it affect broadhead flight? Unless the broadhead just amplifies an existing problem??

[Hydestik]

Both arrows are the same length ? Have you tried shooting bare shafts ? This will rule out fletching contact .

[Sika]

Both arrows are the same length ?

Yes

[hoyt21]

I'd try a twist on each side of the yoke or a twist in or out of bottom of control
Cable

[hoyt21]

Been along time since I've tuned a Hoyt. Enewman could verify or correct what was stated by myself

[JakeGraves]

A broad head will definitely amplify a problem as you are adding another steering wheel.

[TomB]

The little raptor vanes that come on the GT's.

I agree, that could be a problem...but why would it affect broadhead flight? Unless the broadhead just amplifies an existing problem??

This. Broadhead amplifies the clearance issue. Move the “football” down a little in the cable. You can actually film it with the slow motion feature on an I phone and see if it is dropping fast enough. Some drop aways will “bounce” too and catch a vane after it has dropped.

[jake-1024]

The little raptor vanes that come on the GT's.

I agree, that could be a problem...but why would it affect broadhead flight? Unless the broadhead just amplifies an existing problem??

I’m definitely no expert, but it seems like that’s pretty much the rule of thumb. The broadheads steer the arrow more than a field tip does. And it makes sense that if the vanes are contacting the rest it would throw the front end of the arrow down making the arrows shoot low. I’ve never done it myself, but have heard you can spray the back end of the arrow with foot powder spray and that will tell you if there is contact.

[agtex42]

Broadheads amplify everything! It does sound like rest timing might be worth examining. You want the timing marks to align on the rest during the last inch of your draw cycle, sometime following the factory instructions the rest is locked up too early which causes clearance issues (stays up too long). I usually tie my cord in and leave extra on the rest side of the cord for fine tuning, but if they used the "football" clamp you might have some room to adjust the timing of the rest as described above without having to take it back to the shop.

Saw the suggestion for foot powder for checking contact issues, I've had good results with lipstick on the leading edge of the vanes in the past as well.

[JakeGraves]

My advice would be to strip fetching off of one arrow and shoot with field point (definitely don't try with broad head). Try to tune your rest to this eliminating possibility of fletching contacting rest since it's a bare shaft. Once you move rest to get a bullet hole without fletching, shoot your normal arrow with field point, then broad head. A fletching clearance issue will stick out like a sore thumb.

[enewman]

Sika I can help. But last time I tried you basically told me to get lost. So I don't mind helping. But pm me if you do