Heavy-arrow tuning help

[moxford]

So I decided to try something different and build "heavy" arrows.

Bow
2015 Hoyt Nitrium 32 LD (Long-draw) set at 32" DL
80 lb limbs turned down to about 76 lbs

Arrows
.200 Gold Tip Kinetic Kaos @ 30" (longest they make)
75gr Easton HITs
300gr bullet-points to match 300gr broadhead+insert combo
3x 2.5" Blazer vanes (~18 gr)
20gr or so in the nock area

TL;DR - FOC and momentum for days

It's big. It's slow. It's quiet. My arrows regularly disappear past the nock into haybales at 20 yards unless I hit completely virgin hay. Pulling them out of just about any target usually requires an arrow-puller. It's overkill for, well, just about everything but it's fun.

Issue: They group well, but I'm having an issue while paper-tuning and keep ending up "nock left" just a little.
The normal cure: Move the rest to the right.
Problem: The drop-away is close to the riser already and doesn't have much/any more room to move. Moving it hasn't really helped to this point.
Mitigation: The super-heavy tips and long-shafts seem to pull it back into line pretty darn quick, well under 10 yards. But I'd really like to get most/all of that vibration (paradox) out of the arrow to begin with. =D

Theory: The heavy tips are causing the spines to weaken too much even with .200 shafts
Next step: I'm going to try shooting with some 125s and see if it clears up (or at least makes a difference)

I can definitely make it worse by moving the rest the wrong way, but centerline it's a little off and moving it right (even as far as the riser) doesn't seem to make a difference in the tear.

Does anyone have other ideas on how to tune outside of dropping the point-weight?

Thanks in advance!

-mox

 

[OR Archer]

You're a bit weak on spine with that much weight up front at those specs. However you should be able to get it to tune. First thing I would do is reset you rest to center. Recheck the timing also. If timing is good I would reshoot it through paper and see how large the tail left tear is. If you are at say a half inch start with one turn in the left yoke and one turn out of the right yoke. That should reduce the tear by over half. From there just do half turns in/out of the yokes. Probably wont take more than 2 full turns in out of the yokes. That's the basics of how I would approach it.

Now this is all provided you have a proper front grip and good anchor point and that you dont punch the trigger lol

 

[5MilesBack]

3x 2.5" Blazer vanes (~18 gr)

Are your Blazer vanes really 2.5"? If so, they may not be Blazer vanes.

The heaviest I've tried was a .300 spine arrow with the 75gr HIT and 210gr Silverflame BH at 32 1/2" draw at 71lbs, and they actually tuned really well in a binary cam bow. But with the Hoyt you can definitely do some yoke tuning to try and clean it up.

I've seen some pretty awkward looking arrow alignments in some bows when guys try to tune something out with just the rest. If you can't fix it with the yokes and a good centershot......I'd scrap the 300gr point idea and shoot something more realistic.

Or you can get the Black Eagle Rampage 150's and play around even more.

 

[moxford]

Thanks for the ideas OR Archer, will try yoke-tuning.

5MilesBack, right, 2" vane not 2.5" - good catch.

 

[xcutter]

Sounds like your arrows might be too weak. Might be hand placement also. Hard to tell though without watching you shoot.

 

[5MilesBack]

You can also turn your bow down to see if you are weak.

 

[moxford]

Or you can get the Black Eagle Rampage 150's and play around even more.

Originally avoided those because they're 16 gpi compared to the 11.2 gpi of the Kaos. It makes for a much heavier arrow overall and also hurts FOC for the same weight-class arrow. On paper anyways. =)