Am i using the wrong setup?

[remy5]

Hey everyone. I just got back into archery and have been bow hunting for the past 2 years. Unfortunately, I haven't been able to get a shot off. However, this past weekend, I did get a shot off at some birds. After some shots, I realized the flight of my arrows were crooked and went right. My bow was sighted in at a local archery shop using different arrows than what I have now. I hunt mostly elk and mule deer. I'm currently using bear species ev with a 30.5" draw length and 60lb weight. My current arrow setup is a 340 spine - Easton 6mm 340 sonic (standard length, didn't cut. I think they came in at 31"? Maybe 32) 18g insert and a 125g broadhead. I'm curious if my arrow setup is incorrect. If I'm using the wrong spine and broadhead grain.

All the charts I see are over my head when it comes to what I should be shooting, as well as all giving different information. If anyone has any advice, I would greatly appreciate it!

 

[remy5]

Sorry, just found they're 31.5" default for the arrows I have.

 

[nphunter]

They show a little weak at that length, if they fly well it really doesn't matter, they aren't too far off. If you cut them down to 29" they would be perfect, I would cut them anyway personally but I don't like arrows longer than necessary unless I have to make them that way due to tuning with my recurve.

I would just shoot it and not worry about it, if you feel like you're having accuracy issues try cutting a couple to 29" and shoot them and see if it makes a difference. I doubt you will notice any difference.

 

[SDHNTR]

That’s a long arrow and you have some point weight. I don’t know that bow, but with most modern cammed bows you’d be borderline underspined to downright underspined.

I’d get .300 spined arrows (preferably), or cut an inch or so off existing arrows (if you can) or drop down to a 100gr head.

It’s hard to be over spined with a mechanical release. Err on the side of stiffness.

 

[blkqi]

You might be a bit underspined. I would re-tune the the bow for each arrow setup anyway. Was it ever tuned to begin with? Sighting in and tuning are two different beasts.

 

[remy5]

That’s a long arrow and you have some point weight. I don’t know that bow, but with most modern cammed bows you’d be borderline underspined to downright underspined.

I’d get .300 spined arrows (preferably), or cut an inch or so off existing arrows (if you can) or drop down to a 100gr head.

It’s hard to be over spined with a mechanical release. Err on the side of stiffness.

I thought the arrow might be too long. I was going to measure as most charts state of measuring at full draw, so I could see where it should actually be. Would dropping to 100gr head solve this? Or should I get a stiffer spine? Most charts I see, state to go to 300-340 spine so I figured with mine being 340 it would be fine; but after shooting it doesn't feel that way.

 

[remy5]

You might be a bit underspined. I would re-tune the the bow for each arrow setup anyway. Was it ever tuned to begin with? Sighting in and tuning are two different beasts.

It was tuned and sighted for the first pin (15 yrds) when it came into the shop. Or so I was told lol. Most charts I'm reading seem to say that I should be between 300-340 with my length and front end weight/draw weight. I was thinking of going to a 300 spine, but wasn't sure if I'd have to change my front end weight to a 100gr broadhead

 

[SDHNTR]

I thought the arrow might be too long. I was going to measure as most charts state of measuring at full draw, so I could see where it should actually be. Would dropping to 100gr head solve this? Or should I get a stiffer spine? Most charts I see, state to go to 300-340 spine so I figured with mine being 340 it would be fine; but after shooting it doesn't feel that way.

Doesn’t feel that way? Feelings shouldn’t matter. How does it shoot? Compare fixed blade broadhead flight to field point flight. That will tell you a lot. Cutting and/or dropping to 100gr will definitely help, but you don’t want your arrow too light.

If it were me, provided I could keep my overall arrow weight over 425gr, I’d cut (keeping BH well out in front of rest at full draw) and shoot a 100gr head. If not, I’d get 300 spined arrows.

 

[SDHNTR]

It was tuned and sighted for the first pin (15 yrds) when it came into the shop. Or so I was told lol. Most charts I'm reading seem to say that I should be between 300-340 with my length and front end weight/draw weight. I was thinking of going to a 300 spine, but wasn't sure if I'd have to change my front end weight to a 100gr broadhead

Your last sentence doesn’t make sense. Moving to a .300 spine is going stiffer, thus allowing better use of a heavier 125gr head, not a 100.

I can tell from your questions you’d benefit from taking the bow into a competent shop and having it looked over.

 

[Bump79]

That’s a long arrow and you have some point weight. I don’t know that bow, but with most modern cammed bows you’d be borderline underspined to downright underspined.

I’d get .300 spined arrows (preferably), or cut an inch or so off existing arrows (if you can) or drop down to a 100gr head.

It’s hard to be over spined with a mechanical release. Err on the side of stiffness.

This ^^^

 

[remy5]

Doesn’t feel that way? Feelings shouldn’t matter. How does it shoot? Compare fixed blade broadhead flight to field point flight. That will tell you a lot. Cutting and/or dropping to 100gr will definitely help, but you don’t want your arrow too light.

If it were me, provided I could keep my overall arrow weight over 425gr, I’d cut (keeping BH well out in front of rest at full draw) and shoot a 100gr head. If not, I’d get 300 spined arrows.

What I meant by doesn't feel that way is the arrow isn't flying straight after release and tilts. I have no issues with swapping broadheads (I was going to anyway but wanted this figured out first before I bought the wrong weight). The bh is about an inch or so over the rest at full draw currently.

As for the last sentence that you referred to, I meant swapping to a 100gr bh for the current setup, not for if I go to a 300 spine. I'm all over the place with everything right now and not expressing information correctly. I sincerely apologize.

As for taking it in, I was definitely thinking about this since I'm going to pick up new bh and target. I'm not sure if you have one close, but would you recommend scheels? There's a few local shops that I like as well, but they usually don't have the greatest selection of bh or targets in store so wanted a 1 stop shop, but don't mind if I need to take the extra stop for my bh and target.

 

[Mighty Mouse]

Your bow may be out of tune. Try shooting a broadhead tipped arrow followed by a field point tipped arrow at the same spot on a target. Repeat this several times and pay attention to where the BH lands relative to the FP. If there's a consistent difference in point of impact, make adjustments per the charts below to bring BH and FP POI together. The quickest/easiest way to broadhead tune is to move your rest. The "right" way to do it is to keep the rest at/near 13/16" centershot (horizontal distance from inside of riser to centerline of arrow) with the arrow running level through the Berger hole (threaded hole in riser for mounting rest) and tune via cam adjustment. However, adjusting cams generally requires a bow press. On your particular bow, horizontal cam tuning would be done by adjusting the amount of twist in the yokes attached to your upper cam (aka, idler wheel).


Spine charts/calculators are going to say that your arrow is on the weak side (i.e., that it's bending too much during the shot). However, dynamic arrow spine is not an exact science, and the recommendation given by a spine chart/calculator should be viewed as a rough starting point, not as a hard-and-fast requirement for good arrow flight. Your current arrows may fly just fine once your bow is tuned. If you do struggle to achieve a consistent POI when shooting broadheads, you could try stiffening your arrow's dynamic spine by reducing the point/head weight, shortening the shaft, reducing your draw weight, or switching to a shaft with a stiffer static spine (i.e., 300 spine).

FWIW below is qSpine/OT2Go output for your current arrow and a hypothetical shorter arrow with lighter head. Again, it may not be necessary to change anything about your current arrow, but I wanted to demonstrate how shaft length and point weight affect dynamic spine. I realize that both arrows say Easton 6mm Aftermath instead of 6mm Sonic; the current version of this app doesn't include 6mm Sonics in its arrow list, but arrow make/model doesn't actually affect the dynamic spine calculation.

Bow inputs: 320 fps IBO, 60# DW, 30.5" DL, 30" ATA, 6.75" BH, 80% LO
Arrow 1 inputs: 31.5" C2C, 125 gr head, 18 gr insert, 9 gr nock, 3 vanes at 7 gr each
Arrow 1 dynamic spine: .029" weak

Arrow 2 inputs: 30" C2C, 100 gr head, 18 gr insert, 9 gr nock, 3 vanes at 7 gr each
Arrow 2 dynamic spine: .002" weak

 

[Jethro]

I can tell from your questions you’d benefit from taking the bow into a competent shop and having it looked over.

Most definitely.

Best thing you could do is post up where you’re from and let someone recommend a good shop local to you.

“You were told the bow was tuned and sighted”? Your hunting with different arrows than bow was sighted in with. Not good. Get with a competent shop.

 

[remy5]

Most definitely.

Best thing you could do is post up where you’re from and let someone recommend a good shop local to you.

“You were told the bow was tuned and sighted”? Your hunting with different arrows than bow was sighted in with. Not good. Get with a competent shop.

Yeah, I thought this part was weird. I was out of state on a business trip and came back the night before the season started and haven't really done anything since. My wife took it in with my arrows but she said it didn't look like they were using my arrows for any of it. I'm currently in the greater Phoenix area. My wife originally took it to Ross outdoors, which we were told was good but seems like that may not be the case.

 

[SDHNTR]

What I meant by doesn't feel that way is the arrow isn't flying straight after release and tilts. I have no issues with swapping broadheads (I was going to anyway but wanted this figured out first before I bought the wrong weight). The bh is about an inch or so over the rest at full draw currently.

As for the last sentence that you referred to, I meant swapping to a 100gr bh for the current setup, not for if I go to a 300 spine. I'm all over the place with everything right now and not expressing information correctly. I sincerely apologize.

As for taking it in, I was definitely thinking about this since I'm going to pick up new bh and target. I'm not sure if you have one close, but would you recommend scheels? There's a few local shops that I like as well, but they usually don't have the greatest selection of bh or targets in store so wanted a 1 stop shop, but don't mind if I need to take the extra stop for my bh and target.

It’s rare that a big box store has talented help in the archery tuning department. I’d take it to a specialized archery shop.

 

[TX_hunter]

If you want to confirm that spine is your issue for free, take a few turns out of your limb bolts (reduce draw weight). If that improves arrow flight, then you know you're going in the right direction and you can then proceed with a stiffer arrow, or by cutting your existing arrow. I like a 29" arrow myself at a 30" draw length.
I agree with the responses above that you need to shorten your arrow, drop point weight or go to a 300 spine.

If you want to diagnose yourself, watch some videos on youtube on basic bow setup. (setting nocking points, installing rest, etc.) There is a lot of good information out there.
We can also help.

Send the following picures:
Shot straight down on the bow, with arrow nocked, and limb bolts aligned. (Looking to see if arrow rest is running straight, or kicking out left/right.

A shot from the side showing the arrow nocked on the rest, with the string vertically. Need to see if the arrow is running straight or uphill/downhill.

You can also build a DIY paper tuning setup. Shoot your arrow through paper, and post a picture of the tear. You can also turn the draw weight down and see how the tear changes. This will help diagnose a spine issue.

 

[5MilesBack]

Take 2-3" off those arrows (depending on your rest) and you'll be fine. But you will also need to sight in for the new arrows, and tune the bow to them with your shooting. I have almost a 33" draw length (shoot 30" arrows), and I can easily tune to shoot 340's at 60lbs with 125's. You shouldn't have any issues with 340's.

 

[Bigborealaska]

Your bow may be out of tune. Try shooting a broadhead tipped arrow followed by a field point tipped arrow at the same spot on a target. Repeat this several times and pay attention to where the BH lands relative to the FP. If there's a consistent difference in point of impact, make adjustments per the charts below to bring BH and FP POI together. The quickest/easiest way to broadhead tune is to move your rest. The "right" way to do it is to keep the rest at/near 13/16" centershot (horizontal distance from inside of riser to centerline of arrow) with the arrow running level through the Berger hole (threaded hole in riser for mounting rest) and tune via cam adjustment. However, adjusting cams generally requires a bow press. On your particular bow, horizontal cam tuning would be done by adjusting the amount of twist in the yokes attached to your upper cam (aka, idler wheel).
View attachment 655208View attachment 655207

Spine charts/calculators are going to say that your arrow is on the weak side (i.e., that it's bending too much during the shot). However, dynamic arrow spine is not an exact science, and the recommendation given by a spine chart/calculator should be viewed as a rough starting point, not as a hard-and-fast requirement for good arrow flight. Your current arrows may fly just fine once your bow is tuned. If you do struggle to achieve a consistent POI when shooting broadheads, you could try stiffening your arrow's dynamic spine by reducing the point/head weight, shortening the shaft, reducing your draw weight, or switching to a shaft with a stiffer static spine (i.e., 300 spine).

FWIW below is qSpine/OT2Go output for your current arrow and a hypothetical shorter arrow with lighter head. Again, it may not be necessary to change anything about your current arrow, but I wanted to demonstrate how shaft length and point weight affect dynamic spine. I realize that both arrows say Easton 6mm Aftermath instead of 6mm Sonic; the current version of this app doesn't include 6mm Sonics in its arrow list, but arrow make/model doesn't actually affect the dynamic spine calculation.

Bow inputs: 320 fps IBO, 60# DW, 30.5" DL, 30" ATA, 6.75" BH, 80% LO
Arrow 1 inputs: 31.5" C2C, 125 gr head, 18 gr insert, 9 gr nock, 3 vanes at 7 gr each
Arrow 1 dynamic spine: .029" weak
View attachment 655211
Arrow 2 inputs: 30" C2C, 100 gr head, 18 gr insert, 9 gr nock, 3 vanes at 7 gr each
Arrow 2 dynamic spine: .002" weak
View attachment 655210

This ^^

 

[michaelt3719]

I'm no expert but I did the pinwheel stuff and it showed i was a Touch underspined with my 28in 340 spine arrows at 64lbs with 160 gr up front. (100 gr bh, 12gr insert plus 50gr fact weight) So I cut them down to 27.5. Field tips papertuned great and flew like razors, and I could get a few fixed blades to fly good but it was a struggle. I finally decided to go up to 300's and not have to cut them so short, as 27.5 was pushing it for my 29in draw length. I wish I'd done it sooner. I'm just getting better broadhead flight, more consistently. So my experience reinforces that line about when in doubt/if you're at all borderline on spine, go with the stiffer spine--at least for good fixed blade broadhead flight.
I've read that you need Some flex off the bow, but I think in general less flex = straighter bh flight. So in your case, yes you might be ok with a 340 spine 30in arrow at 60lbs if you stay light on the front end or only shoot field tips, but if you ever shoot fixed blade broadheads I'm betting 300s would work better.