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Discussion Starter · #1 ·
Hey everyone. I’m fairly new to archery hunting. I killed my first buck this year but I’ve been shooting archery for years. I’ve looked at plenty of charts and had one guy tell me my arrows are underspined for my length and draw weight. I’m shooting at between 70-72 pounds with a 30 in draw length and roughly a 30.5 inch arrow. I’m shooting easton bloodlines 330s. According to charts im underspined and my arrows “shouldn’t group that well” but my groups up to 40 yards are all very well and I’m without a doubt confident in shooting an animal at 40 yards. The buck I shot this year I shot at about 15 yards with a rage and hit him in the shoulder. Penetrated well but didn’t pass through. I’ve been thinking if my arrows were correctly spined if they would have passed through. According to charts I should be somewhere in the 260-240 What do you guys think (stiffness wise) I should be shooting??
 

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What is your broadhead weight?
 
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OK, according to the spine calculator I have, given the spec you've quoted you should be looking for a 250 spine Shaft with 125grain on the point or a 270 spine with 100grain point. Personally I'd go for the 125grain point to push your FOC forward a bit to give you the trough and though hits (there will be folk on here who will encourage even more point weight).
I personally prefer to go slightly heavier on spine as it's better to be a little over spine than it is under spine, so I shoot a 350spine on a 28" @ 55# with 125grain fixed blade up front, giving me a 438grain arrow with an FOC of about 15%. That gives me all the smack I need. Incidentally, my practice arrows are the same spec but come out at 406grains with 125grain field point. The difference in point of impact is not discernable between the two sets of arrows over hunting ranges (40yards tops) but a ranges 60yards plus it does start to show.
 
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Hey everyone. I’m fairly new to archery hunting. I killed my first buck this year but I’ve been shooting archery for years. I’ve looked at plenty of charts and had one guy tell me my arrows are underspined for my length and draw weight. I’m shooting at between 70-72 pounds with a 30 in draw length and roughly a 30.5 inch arrow. I’m shooting easton bloodlines 330s. According to charts im underspined and my arrows “shouldn’t group that well” but my groups up to 40 yards are all very well and I’m without a doubt confident in shooting an animal at 40 yards. The buck I shot this year I shot at about 15 yards with a rage and hit him in the shoulder. Penetrated well but didn’t pass through. I’ve been thinking if my arrows were correctly spined if they would have passed through. According to charts I should be somewhere in the 260-240 What do you guys think (stiffness wise) I should be shooting??
Blah, blah, blah is what your going to hear about how under you are. BOTTOM LINE they are working for you, ya don't fix what ain't broke! By your own admission your not broke.
 

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Blah, blah, blah is what your going to hear about how under you are. BOTTOM LINE they are working for you, ya don't fix what ain't broke! By your own admission your not broke.
Continually shooting under spine arrows isn't good for the bow in the long run though.
 

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First off, have you bare shaft tested your arrows for tuning and flight? What you are looking for is a BS that impacts (|) with a fletched arrow....not (\) or (/). That will reveal a lot more about your setup than simply shooting fletched arrows at whatever distance. A good shooter can group a marginally tuned bow with pretty poor actual arrow flight.....a shooting machine can group any arrow with any bow as well.

Since you are shooting a mechanical with folded blades, there is no reason you cannot cut down one of your shafts to 30" or even 29.5" and test it out.....that increases dynamic spine of your current 330 shafts. My DL on a '19 Elite Ritual 35 is 29 1/4" and I'm shooting 28 1/4" Easton Axis 6mm 340 at 61# with a 100 gr point.....a full inch shorter than my DL with a Hamskea rest.....with a goodly amount of arrow in front of the launcher.

If you can get a 300 spine to test against your 330's, it will also be revealing. I shot 400's out of an older single cam bow just fine at 60, but add a fixed BH and they were not nearly as consistent as a 340. If you don't want to buy new arrows right now, turning your bow down a few pounds also makes a difference. Quite honestly, you don't need 70-72 to kill North American game.....67 would be just as effective.
 

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Discussion Starter · #9 ·
OK, according to the spine calculator I have, given the spec you've quoted you should be looking for a 250 spine Shaft with 125grain on the point or a 270 spine with 100grain point. Personally I'd go for the 125grain point to push your FOC forward a bit to give you the trough and though hits (there will be folk on here who will encourage even more point weight).
I personally prefer to go slightly heavier on spine as it's better to be a little over spine than it is under spine, so I shoot a 350spine on a 28" @ 55# with 125grain fixed blade up front, giving me a 438grain arrow with an FOC of about 15%. That gives me all the smack I need. Incidentally, my practice arrows are the same spec but come out at 406grains with 125grain field point. The difference in point of impact is not discernable between the two sets of arrows over hunting ranges (40yards tops) but a ranges 60yards plus it does start to show.
Thanks for the advice. I appreciate it. I’m looking currently at some 240s since they are the same arrow I’m currently shooting just stiffer. Is that fine? I know it’s on the stiffer side but as you stated it’s better to be over spined then under. Am I right?
 

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Discussion Starter · #10 ·
Blah, blah, blah is what your going to hear about how under you are. BOTTOM LINE they are working for you, ya don't fix what ain't broke! By your own admission your not broke.
Yeah that’s true. When it comes to arrow stiffness and stuff I’m very new so I’m trying to get an idea as to what people who are more experienced have to say. I get what your saying. For this season I don’t plan on changing since it’s worked so far like you said. But for next season I plan on switching so I can be a little more accurate further out. For example up to 40 yards I’m dead accurate. Once I get to 50 my shot fades to the left about 3 inches. It could be my form and many other things but if it’s good up to 40 then I have a feeling it’s the arrows or something to do with them. But like you said “don’t fix what ain’t broke”. Couldn’t be any more true!
 

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Discussion Starter · #11 ·
First off, have you bare shaft tested your arrows for tuning and flight? What you are looking for is a BS that impacts (|) with a fletched arrow....not (\) or (/). That will reveal a lot more about your setup than simply shooting fletched arrows at whatever distance. A good shooter can group a marginally tuned bow with pretty poor actual arrow flight.....a shooting machine can group any arrow with any bow as well.

Since you are shooting a mechanical with folded blades, there is no reason you cannot cut down one of your shafts to 30" or even 29.5" and test it out.....that increases dynamic spine of your current 330 shafts. My DL on a '19 Elite Ritual 35 is 29 1/4" and I'm shooting 28 1/4" Easton Axis 6mm 340 at 61# with a 100 gr point.....a full inch shorter than my DL with a Hamskea rest.....with a goodly amount of arrow in front of the launcher.

If you can get a 300 spine to test against your 330's, it will also be revealing. I shot 400's out of an older single cam bow just fine at 60, but add a fixed BH and they were not nearly as consistent as a 340. If you don't want to buy new arrows right now, turning your bow down a few pounds also makes a difference. Quite honestly, you don't need 70-72 to kill North American game.....67 would be just as effective.
No I have not done that because I buy my arrows already pre cut with fletchings and inserts equipped online out of state. I live in south Florida so there aren’t any bow shops that do that down here. For the most part my groups are very good. Up to 40 yards my shots are within 1-3 inches of each other. Once I get to that 50 yard mark my shot is a little off. It could be that I’ve never really shot that far and I’m getting use to it. But it’s just something I was thinking could be the reason for that
 

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No I have not done that because I buy my arrows already pre cut with fletchings and inserts equipped online out of state. I live in south Florida so there aren’t any bow shops that do that down here. For the most part my groups are very good. Up to 40 yards my shots are within 1-3 inches of each other. Once I get to that 50 yard mark my shot is a little off. It could be that I’ve never really shot that far and I’m getting use to it. But it’s just something I was thinking could be the reason for that
All it takes to make a bare shaft is carefully cutting off the vanes from one of your arrows. It would be worth the cost of a few vanes to determine how your current shafts are actually flying. Shoot indoors at close range to start....8-10 yards if you decide to try a bare shaft. If you have a local shop, tell them you are test tuning and ask them to cut down the bare shaft from the nock end 1/2" and retry to compare. Pull the nock out, cut and reinstall the nock at the shorter length. Again, one shaft is worth determining what you have vs. buying a new dozen according to a computer program calculator. This is the first step in learning bow system tuning and being independent....if you so choose....some do not.
 

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Spine is a window......not a set point you have to achieve. I would think you are on the 'weaker" side but if it's shooting well then you are good.
 

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Continually shooting under spine arrows isn't good for the bow in the long run though.
How is that? I think you have spine and weight confused. If you shoot the same brand arrow they get lighter as the spine decreases and vice versa but spine can't damage a bow at all.
 

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Thanks for the advice. I appreciate it. I’m looking currently at some 240s since they are the same arrow I’m currently shooting just stiffer. Is that fine? I know it’s on the stiffer side but as you stated it’s better to be over spined then under. Am I right?
My personal opinion you should be good with the 240's with your present set up. Don't go overboard in buying quantity though (a mistake I made). Getting the right arrow/bow/you combination can be a time consuming and expensive exercise, but worth it in the end. As stated in another post, you may want to consider dropping your poundage if possible, you'll be thankful in the long run.
I used to shoot Easton power flights, not the most expensive arrow on the market (budget really) but from a reputable stable. I couldn't get on with them. I eventually found some shafts from Accmos (yeah, I know Chinese), but they are consistent, I'm on my third batch from them. I had to recalibrate my sight as they shoot flatter and tighter on targets and they don't break the bank either. I'm not saying they're right for you or any one else, but sometimes it can pay dividends if you think outside the box. So buy your arrows half dozen at a time until you find the right one.
As for hunting range, if you can hit a paper plate sized circle 8 out of 10 times up to a certain range, that's your hunting range. Personally, I keep it below 40yards regardless, as I think beyond that, the arrow is in flight for too long and the beast can move in the meantime. But that is just my thoughts on it.
Above all, have fun and good hunting.
 

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Discussion Starter · #17 ·
My personal opinion you should be good with the 240's with your present set up. Don't go overboard in buying quantity though (a mistake I made). Getting the right arrow/bow/you combination can be a time consuming and expensive exercise, but worth it in the end. As stated in another post, you may want to consider dropping your poundage if possible, you'll be thankful in the long run.
I used to shoot Easton power flights, not the most expensive arrow on the market (budget really) but from a reputable stable. I couldn't get on with them. I eventually found some shafts from Accmos (yeah, I know Chinese), but they are consistent, I'm on my third batch from them. I had to recalibrate my sight as they shoot flatter and tighter on targets and they don't break the bank either. I'm not saying they're right for you or any one else, but sometimes it can pay dividends if you think outside the box. So buy your arrows half dozen at a time until you find the right one.
As for hunting range, if you can hit a paper plate sized circle 8 out of 10 times up to a certain range, that's your hunting range. Personally, I keep it below 40yards regardless, as I think beyond that, the arrow is in flight for too long and the beast can move in the meantime. But that is just my thoughts on it.
Above all, have fun and good hunting.
Thanks for all of your advice. Yes I have made that mistake in the passed so I only buy them in half dozens. Also so that when season comes most of them have been shot or destroyed from target practice so my next season I can have the option to use the same ones or try a different set. Also, with the 240s should I shoot 125 grains or 150? Is one better then the other for the arrow stiffness?
 

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Blah, blah, blah is what your going to hear about how under you are. BOTTOM LINE they are working for you, ya don't fix what ain't broke! By your own admission your not broke.
But, the OP hasn’t stated if he’s shot broadheads, and I’m pretty sure not fixed heads at all.

The spine is weak, and when you start using fixed you’ll likely run into issues.
 

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Thanks for all of your advice. Yes I have made that mistake in the passed so I only buy them in half dozens. Also so that when season comes most of them have been shot or destroyed from target practice so my next season I can have the option to use the same ones or try a different set. Also, with the 240s should I shoot 125 grains or 150? Is one better then the other for the arrow stiffness?
I would say try it. You can pick up half dozen field points cheap enough and try them at at target. Yes broadheads, especially fixed blades can have an effect on arrow fight. Just be aware, increasing the point weight can have the effect of 'softening' your spine on the arrow. So, get hold of some 100, 125 and 150grain field points and see which shoot the most consistently for you. If you can see some slow motion footage of an arrow shot from a compound, you will see the Shaft flex at the point of release. This is because the front end of the arrow wants to stay where it is but the back end is being pushed forwards buy the string. The greater the weight at the point the greater the flex. The quicker the arrow Shaft recovers an stabilises Once it's left the bow, the more accurate it's flight.
Additionally taken to extreme, softer arrows tend to be lighter and flex more. We all know the potential results of a dry fire, but there is also the potential for repeated stresses in the arrow Shaft can result the higher risk of failure during the shot cycle as well as increased stresses on the bow limbs.
 
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Discussion Starter · #20 ·
But, the OP hasn’t stated if he’s shot broadheads, and I’m pretty sure not fixed heads at all.

The spine is weak, and when you start using fixed you’ll likely run into issues.
I’ve only shot mechanicals. Well I’ve only shot one mechanical at an animal. Great huge hole at 15 yards. Didn’t get a pass through but I hit high on the shoulder. Arrow still penetrated enough to hit the opposite shoulder but not go through
 
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