Adjust spine, tophats, or leave alone?

rileybassman

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Sup all,

Dialing in my new V3 last couple weeks... It's been shooting great - but I'm trying to make sure I'm as tuned as I can/should be.

I've got a slight left tear, arrow flight seems to be good from what I can tell, and broadbeads are flying with my fieldpoints pretty well out to 60.

I'm shooting 28" draw at 65 lbs at about 270 fps.

Arrows are kinetic pierce 340 spine - 28", 4 fletch AAE hybrids (36 grains on the back) 125 grain tips with 40 grain outserts.

Arrow weight is 440 grains. FOC is about 14%.

I have my rest almost a 1/16" off center shot (towards riser) - it tuned the broadbeads, but didn't really change my paper tears that much.

From what I have read, a tophat adjustment may be in order... But then I was wondering if maybe I'm slightly under spined... One calculator (victory) said I was fine, one chart said I was under spined.

Looking for thoughts... Is it worth chasing this and trying to get tuned with a 13/16 center shot using top hats, should I lower my tip weight and shoot 100 grain tips(lowering arrow weight to 415 grains).. or should I leave it alone and stop overthinking it lol.

I'd like to use these arrows if possible as I have a dozen... I also already have half a dozen 125 iron wills ready.. so I'm hoping arrow spine is ok.

Thanks!




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Mighty Mouse

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I've got a slight left tear, arrow flight seems to be good from what I can tell, and broadbeads are flying with my fieldpoints pretty well out to 60.
Looking for thoughts... Is it worth chasing this and trying to get tuned with a 13/16 center shot using top hats, should I lower my tip weight and shoot 100 grain tips(lowering arrow weight to 415 grains).. or should I leave it alone and stop overthinking it lol.
You don't hunt shooting through paper. Broadheads hitting alongside field points (within your shooting ability out to your maximum effective range) is the ultimate goal of tuning; if you've achieved that, leave it alone and stop overthinking it.
 

Zac

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Broadheads hitting with field points is the ultimate goal. However I don't think that is happening if you have a left tear. One of the Top hats will have the cam shimmed to the right from the factory. You can simply switch that Top Hat configuration so that both cams are shimmed to the left. You may be able to go back to 13/16ths at that point. If you are unable to get BHs, and FTs to hit together at that point, you can try taking some turns out of your limb bolts. Mathews are extremely forgiving when it comes to multiple spine configuratoins so I think what you have should work great.
 

Kularrow

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What was the rationale behind shooting through paper again after broadhead tuning? Assuming you did a paper tune when you set the bow up?
 
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rileybassman

rileybassman

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What was the rationale behind shooting through paper again after broadhead tuning? Assuming you did a paper tune when you set the bow up?
Mostly because my center shot was between 11 and 12/16" after broadbeads tuning... I've only had the bow for 2 weeks so this paper tune happened maybe a week back and I'm just pondering the results.

When the shop set it up there was a slight left hand tear... They said to shoot the string in and then check again after a few hundred shots... I wasn't impressed with them but they were my only Mathews dealer in town and they had what I wanted in stock. When I shot it in and came back they said leave it for a week and they would check the tune. I wasn't willing to leave it and let someone else check the tune when I wanted to be able to participate/shoot it. I took it to our other shop and they said they don't really paper tune anymore and to check broadbeads tune and go from there.

So I'm on my own for tuning it seams :)

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rileybassman

rileybassman

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I don’t think you are underspined, but a quick check would be to back out the limbs in 1/2 turns and see what happens.
Ok - I can try that... Question, would going from 125 to 100 grain tips accomplish a similar result? I am gonna try and check this later today if I get some time.

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Miflatlander91

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I paper or bareshaft tune to get close then broadhead tune once they hit with field points I keep shooting a broadhead every so often it is easy to let your form get lazy and steer the bh

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rileybassman

rileybassman

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Broadheads hitting with field points is the ultimate goal. However I don't think that is happening if you have a left tear. One of the Top hats will have the cam shimmed to the right from the factory. You can simply switch that Top Hat configuration so that both cams are shimmed to the left. You may be able to go back to 13/16ths at that point. If you are unable to get BHs, and FTs to hit together at that point, you can try taking some turns out of your limb bolts. Mathews are extremely forgiving when it comes to multiple spine configuratoins so I think what you have should work great.
Ok cool - yes I can see the top cam is gapped to the opposite side as the tear and from my reading I want to shim toward the tear. I'm new to some of this and am going to try and pick a press up. I'm a quick study and a tinkerer so I'm sure I can get it..m just trying to find best place to start.

Broadbeads flight has been good - but i also switched to a 4 fletch with a smaller shaft so it's possible some flight issues are being hidden - the smaller shafts are harder to see in flight and the 4 fletch is stabilizing them pretty well as far as I can tell. I've been shooting 3 field tip and 1 broadhead groups for about a week or so and they consistently fly together.

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rileybassman

rileybassman

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You don't hunt shooting through paper. Broadheads hitting alongside field points (within your shooting ability out to your maximum effective range) is the ultimate goal of tuning; if you've achieved that, leave it alone and stop overthinking it.
Sweet... Yea I think I'm close to this point... But I'm also a tinkerer and can bit a bit anal about things like this... I like to feel like I'm as optimized as I can be :) but yea... I'll keep shooting and if it stays good i guess it is good :)

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Mighty Mouse

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Sweet... Yea I think I'm close to this point... But I'm also a tinkerer and can bit a bit anal about things like this... I like to feel like I'm as optimized as I can be :) but yea... I'll keep shooting and if it stays good i guess it is good :)
I hear you. I'm a tinkerer and perfectionist by nature as well. But I've occasionally found myself chasing my tail trying to get a perfect bullet hole through paper and just had to live with a slight tear and move on to bareshaft and broadhead tuning.

FWIW Mathews recommends a centershot measurement of 13/16"±1/16", so anything between 3/4" and 7/8" would still be considered in spec. I personally wouldn't have any qualms about going up to ≈1/8" inside/outside of 13/16". If I needed to go beyond that, I'd be looking at swapping top hats.
Screenshot_20210721-082952.png
 

Zac

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Ok cool - yes I can see the top cam is gapped to the opposite side as the tear and from my reading I want to shim toward the tear. I'm new to some of this and am going to try and pick a press up. I'm a quick study and a tinkerer so I'm sure I can get it..m just trying to find best place to start.

Broadbeads flight has been good - but i also switched to a 4 fletch with a smaller shaft so it's possible some flight issues are being hidden - the smaller shafts are harder to see in flight and the 4 fletch is stabilizing them pretty well as far as I can tell. I've been shooting 3 field tip and 1 broadhead groups for about a week or so and they consistently fly together.

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How far out are you shooting? Also try a bareshaft at the same distance. If you have a left tear your bare shaft should impact right of your fletched shaft. This will let you know if your fletchings are hiding anything.
 
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rileybassman

rileybassman

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How far out are you shooting? Also try a bareshaft at the same distance. If you have a left tear your bare shaft should impact right of your fletched shaft. This will let you know if your fletchings are hiding anything.
Ok... so maybe I'm grasping at straws and need to quit shooting paper/work on form...

Just ran oustide and shot Broadhead, bareshaft, and field point at 20,30,40, and 60 (idk why but I skipped 50 lol).

I think the 40 yard bareshaft must have been me...

One bareshaft ( I thin the 20 or 30) looked like it was going to plane for a sec, but it landed ok... I focused hard on form the further out I got and all 3 seemed to fly ok.

So... with these groups... should I pursue tuning anymore... or shutup and shoot?

20 yards
RbicxZRh.jpg

30 yards
ft3yNWeh.jpg

40 yards
wGzjhILh.jpg

60 yards
z492C0fh.jpg
 

Mighty Mouse

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So... with these groups... should I pursue tuning anymore... or shutup and shoot?
Looks to me like you're pretty well tuned, but only you know if those groups are a good representation of your shooting ability. 20/30/60 yd bareshafts look great, the 40 yd bareshaft looks like a single bad shot. If your bow is out of tune, the bareshaft and BH should be consistently impacting on the same side of the FP. I can't tell which arrow is FP vs. BH, but there doesn't appear to be a consistent pattern that would suggest a need to adjust your tune.
 
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rileybassman

rileybassman

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Looks to me like you're pretty well tuned, but only you know if those groups are a good representation of your shooting ability. 20/30/60 yd bareshafts look great, the 40 yd bareshaft looks like a single bad shot. If your bow is out of tune, the bareshaft and BH should be consistently impacting on the same side of the FP. I can't tell which arrow is FP vs. BH, but there doesn't appear to be a consistent pattern that would suggest a need to adjust your tune.
Yea I called the 40 as I shot... the bareshaft and broadheads flip flopped sides twice... so I think it's probably about the limit of my shooting ability at this time.
 
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rileybassman

rileybassman

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If you change anything on that bow after shooting groups like that with bareshaft, broadhead, and FP; you deserve to chase your tail until hunting season.

Leave it alone and go kill stuff. Nice shooting!


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Lol thanks... yea that's the first I had taken bareshafts out past 30 yards... I was a little nervous but decided to go for it - I do feel a bit better now having seen that they seem to be flying better then I thought they would.

Rodger that... I'm gonna just shoot and hopefully go kill stuff :)
 
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