Broadhead tuning issue - RESOLVED

Over the last 5 years I've found that tuning a bow is something that requires patience and an understanding of arrow flight. It probably takes about 2 hours of putting the bow in a press and shooting it to get it in full tune.

My own personal rule is to have my bow set to factory spec. Nocking point and arrow rest perpendicular to strings and running center center through the berger hole with the center of the arrow being 13/16 from the shelf. having the cams properly timed to each other

from what I would call factory zero I would make big changes left/right with yoke tune/cam shimming. and vertical changes with nock point. when its super close make minor changes with the arrow rest since in theory its the directional influence that makes the most finite changes.

I do disagree with the left/right changes being effected by spine stiffness/weakness. Bows are so adjustable that we can account for weakness/stiffness with bow adjustments. Bows older than ~2002 had much less adjustability and weak/stiff spine was part of the tuning process. If you're looking to tune your bow to the max, i'd say everyone should have a 200 or 150 spine arrow for initial paper tuning. In theory, you can't have too stiff of a spine to get your bow shooting straight. The spine does play a role in accuracy and grouping but if your bow isn't squared, spine won't necessarily fix the issue. So if you're looking for the MOST accurate and best grouping, you'll need 3 spines. Dudley made a good video on this last year. He shot the same bow with 3 different spine arrows to show grouping
 
OP, you know one more thing that might help you is to consider swapping out that grip on your DXT. When I shot Mathews of that vintage swapping out, the grip was one of the first things I did on a new bow. That big fat wooden grip is not very conducive to proper hand position. There are lots of options now, but something like a Shrewd grip in a low wrist configuration might help you. For me it was a mandatory change on Matthews.
 
Yeah, MM’s chart makes sense if the rest is so far off center shot to cause that yaw effect with the arrow kicking around the riser and changing directions.

If it’s just a little off, I can see the traditional method working as it’s not enough to make the arrow yaw, and instead it planes, due to the surface area of the blades up front.

Just a theory that makes sense in my pea brain.

Has anyone seen Randy Ulmer’s method of setting center shot? That’s what I do now. Start by ensuring there is little to no cam lean. Set up your bow press so that the bow hangs off the edge of the table or build a bench with an indentation at the middle of the bow so you can hang an arrow down off the string without it hitting the bench/table. Yes the factory spec center shot is a good place to start, but it’s imprecise. Instead, if you press the bow just enough to hold it in place, and let an arrow hang from the string like a plumb bob, it will fall into the natural center shot position. Then set the rest to where the arrow naturally rests without moving it. Of course you can’t have a nock that is too tight. It needs to hang and swing freely on the string to let gravity work. Anyway, when I first saw that method it was one of those “why didn’t I think of that” moments.
 
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