• The SH Membership has gone live. Only SH Members have access to post in the classifieds. All members can view the classifieds. Starting in 2020 only SH Members will be admitted to the annual hunting contest. Current members will need to follow these steps to upgrade: 1. Click on your username 2. Click on Account upgrades 3. Choose SH Member and purchase.
  • We've been working hard the past few weeks to come up with some big changes to our vendor policies to meet the changing needs of our community. Please see the new vendor rules here: Vendor Access Area Rules

Arrow spine and Weight

D

DwadeCham

Well-Known Member
Joined
Feb 23, 2016
Messages
529
I have finally gotten my bow paid for and looking for direction on weight. I want it to pack a punch.

I have a 70# weight, 32" length bow. I have looked around and am struggling to get good direction so thought I would ask around here.

Thanks,
Wade

Sent from my HTC U11 using Tapatalk
 
If you want to pack a punch use a 2 blade fixed broadhead. 70# at 32in will be a missile launcher pretty much no matter if it's a light arrow or heavy. If you are wanting a larger cutting diameter with more blades to push through, then weight will help. But make sure it's strong enough to handle all that force you are applying to it. Hard to beat a solid cut on contact fix blade for strength and penetration. Look at some VPA terminators. That's a solid head that can handle it. A bent tip or blade kills penetration. So does an arrow that isn't flying true, so make sure you got it tuned at all ranges and you will be blowing holes. Some 55-75s or the next spine stiffer will probably be good. All depends on your tip weight. Heavier the tip, the stiffer you will need the arrow to be and you got a long arrow so it's gonna need to be one of the stiffer ones made.
Just go to any arrow manufacturer web page and look up spine selector. Put your info in and it will give you the spine range you need.
 
DwadeCham said:
I have finally gotten my bow paid for and looking for direction on weight. I want it to pack a punch.

I have a 70# weight, 32" length bow. I have looked around and am struggling to get good direction so thought I would ask around here.

Thanks,
Wade

Sent from my HTC U11 using Tapatalk
Click to expand...

I went with really heavy arrows for my bow. They aren't as fast due to the weight, but they carried a lot of momentum when they hit. I primarily did this to make sure to get good penetration on an elk hunt two years ago. I used the Full Metal Jacket arrows with a 125 grain fixed broadhead and easily got through the elk in my profile picture with just the fletchings sticking out the impact side.

I recently bought some axis arrows and instead of having the metal jacket to add weight, I added a weighted insert in the front of the arrow. I was able to get the same total weight of arrow, but greatly improved my FOC.

There is a software package called "archers advantage" that will let you play around with different arrow manufacturers, length, broadhead length etc and help you pick the right spine for the bow and draw weight you are using. I have a copy of it, but it is outdated and likely doesn't contain your bow if it is newer.

Some people choose KE over Momentum, but the way I look at it, it is harder to stop a slow moving train than a fast moving fly...

I personally wanted momentum to push my arrow through. I could run a couple simulations if you want. I would need to know a couple of things.

Bow type, I already have draw length and weight, and perhaps a couple of arrow types you are looking at and perhaps what length of arrow you typically use. I could probably upgrade my software fairly inexpensively if I don't already have the info for your setup.
 
I agree with the above statements. Get a heavy arrow. Something like the full metal jacket arrows and a massive 3 or 4 blade head. You have enough power to send a stop sign through a buffalo! Might as well get a massive broadhead to spill some blood!
 
I'm shooting a 540 grain arrow. 60# draw weight, 30" draw length, .300 spine arrows cut to 29.75 from nock to carbon, 100grain brass inserts at front of arrow, 100 grain tips. Got a devastating pass through on a whitetail shoulder last year. I'm convinced.
 
Erniepower said:
I went with really heavy arrows for my bow. They aren't as fast due to the weight, but they carried a lot of momentum when they hit. I primarily did this to make sure to get good penetration on an elk hunt two years ago. I used the Full Metal Jacket arrows with a 125 grain fixed broadhead and easily got through the elk in my profile picture with just the fletchings sticking out the impact side.

I recently bought some axis arrows and instead of having the metal jacket to add weight, I added a weighted insert in the front of the arrow. I was able to get the same total weight of arrow, but greatly improved my FOC.

There is a software package called "archers advantage" that will let you play around with different arrow manufacturers, length, broadhead length etc and help you pick the right spine for the bow and draw weight you are using. I have a copy of it, but it is outdated and likely doesn't contain your bow if it is newer.

Some people choose KE over Momentum, but the way I look at it, it is harder to stop a slow moving train than a fast moving fly...

I personally wanted momentum to push my arrow through. I could run a couple simulations if you want. I would need to know a couple of things.

Bow type, I already have draw length and weight, and perhaps a couple of arrow types you are looking at and perhaps what length of arrow you typically use. I could probably upgrade my software fairly inexpensively if I don't already have the info for your setup.
Click to expand...
Thanks Ernie. I may take you up on that but would PayPal you the upgrade fee.

Sent from my HTC U11 using Tapatalk
 
Thanks everyone. Just trying to get a solid setup. I am mainly trying to avoid the "speed, speed, speed" mentality. I think that bow is going to be pushing a lot of speed anyway.

Sent from my HTC U11 using Tapatalk
 
I shoot a 65# with 29" draw. Im shooting a 340 spined arrow 28.5 inch long 425 grains and thats with a 100 grain vipertrick broadhead. I have never not blown through a deer. No problems ever with penetration or flight for that matter. I know that im shooting just about 282fps with that setup. Its plenty fast but is more of an overall balanced speed.
 
Long shooter here also: 31" draw/ 29.75" arrow/ 70# holding weight. Not a lot of options for long arrow/heavy draw weight. About the lightest you'll find is the Black Eagle Carnivore. I shot the 250 spine last year with their 42 grain brass insert and 125 grain broadhead. It weighed in at about 480 with a higher FOC. I switched it up this year to the 280 spine FMJ deep six with the standard insert and only 100 grain tip. It weighs in at about 505 with lower FOC.

Either way you're probably pushing 450+ grains for the length of arrow and spines available. I use the Spinal Tap program to build arrows. If you're under or over spined it's a big waste of money.
Sent from my iPhone using Tapatalk
 
You can also sign up for archers advantage online, I've been using it like that.
 
Man, I am struggling with the Archer's advantage program. I can never get anything to say optimum spine.

Sent from my HTC U11 using Tapatalk
 
I wouldn't worry too much about falling smack dab in the middle of the optimum range. It's OK to be a little weak or a little stiff. It's when you're extremely weak or extremely stiff do you start to run into more dramatic tuning and arrow flight issues.
 
DwadeCham said:
Man, I am struggling with the Archer's advantage program. I can never get anything to say optimum spine.

Sent from my HTC U11 using Tapatalk
Click to expand...
Are you at least falling somewhere around the edges of "optimum spine"? If you are you can tweak your draw weight by a couple pounds and your arrow length by a 1/2 inch here of there, add weight to the end of the arrow, etc to get it to be "optimum". If you aren't anywhere close you need to find a different arrow that works for your set up. I find the program to be good but sometimes if you jump around it doesn't update so you have to log out and log in sometimes.
 
redsquirrel said:
Are you at least falling somewhere around the edges of "optimum spine"? If you are you can tweak your draw weight by a couple pounds and your arrow length by a 1/2 inch here of there, add weight to the end of the arrow, etc to get it to be "optimum". If you aren't anywhere close you need to find a different arrow that works for your set up. I find the program to be good but sometimes if you jump around it doesn't update so you have to log out and log in sometimes.
Click to expand...
I think that is what is confusing me. I have had the same arrow tell me it is too weak, slightly weak, and optimum.

Saw a guy on archery talk tell someone with my draw length to back poundage down to 65 lbs, shoot 100 grain, stiffest spine I can in a 30" arrow, 8 inch arrow wrap.

I really wish I had a good local resource. And I have contacted Easton, black eagle, and they just tell me the stiffest spine they sell.

Sent from my HTC U11 using Tapatalk
 
Well...

There's only so much the software is going to be able to guess at. I would worry more about how you're actually shooting than what the software tells you. In the end it's just a guide to tell you what's 'optimal' based off of some formula... not real-world use case. The 'optimum' range is just a recommendation based on equipment specs.

Optimal spine for archers is meant to provide you with the safest, most forgiving arrow to shoot for that setup. You can shoot ultra-stiff logs out of low pound bows all day, but you're likely going to need perfect form and to tune the bow for that setup. And if you're arrows are too weak you run the risk of having them explode on you.

If you're shooting good, groups are good, not getting any crazy paper tear or tuning issues, I wouldn't worry too much about what the software says. Some bows like stiffer spined arrows, some like weaker. Heck some target archers intentionally shoot arrows that are technically extremely weak but adjust their bow for different arrows. Playing with your rest and draw weight gives you lots of ways to tune your bow for different arrows.

I can say at 70lbs draw weight, 30" draw length, without any added arrow weight, you're going to want the stiffest they sell - .300 is my guess - and that will put you slightly weak in the spine. Even without any weight a 30" arrow at 8 or 9gpi is going to be 270 grains excluding vains, nock, and insert - add another 30-40 grains for those items. Smack a 100gr BH on there and you're at a 400 grain arrow. It's plenty of weight to kill just about anything in North America.

If you're wanting super heavy arrows you gotta figure out where you want to compromise. Adding weight to the arrow without something to 'stiffen' it is going to result in a weaker spine, but potentially much higher KE and momentum downrange. You may lose some forgiveness in this setup so you'll have to dial in your form and bow tune.

Use the software as a guide and go from there. In the end the bow will tell you what it likes to shoot, not the software.
 
d_rek said:
Well...

There's only so much the software is going to be able to guess at. I would worry more about how you're actually shooting than what the software tells you. In the end it's just a guide to tell you what's 'optimal' based off of some formula... not real-world use case. The 'optimum' range is just a recommendation based on equipment specs.

Optimal spine for archers is meant to provide you with the safest, most forgiving arrow to shoot for that setup. You can shoot ultra-stiff logs out of low pound bows all day, but you're likely going to need perfect form and to tune the bow for that setup. And if you're arrows are too weak you run the risk of having them explode on you.

If you're shooting good, groups are good, not getting any crazy paper tear or tuning issues, I wouldn't worry too much about what the software says. Some bows like stiffer spined arrows, some like weaker. Heck some target archers intentionally shoot arrows that are technically extremely weak but adjust their bow for different arrows. Playing with your rest and draw weight gives you lots of ways to tune your bow for different arrows.

I can say at 70lbs draw weight, 30" draw length, without any added arrow weight, you're going to want the stiffest they sell - .300 is my guess - and that will put you slightly weak in the spine. Even without any weight a 30" arrow at 8 or 9gpi is going to be 270 grains excluding vains, nock, and insert - add another 30-40 grains for those items. Smack a 100gr BH on there and you're at a 400 grain arrow. It's plenty of weight to kill just about anything in North America.

If you're wanting super heavy arrows you gotta figure out where you want to compromise. Adding weight to the arrow without something to 'stiffen' it is going to result in a weaker spine, but potentially much higher KE and momentum downrange. You may lose some forgiveness in this setup so you'll have to dial in your form and bow tune.

Use the software as a guide and go from there. In the end the bow will tell you what it likes to shoot, not the software.
Click to expand...
Thanks for the input. I know you're right but I have procrastinated and don't have a lot of time to play around much. Probably going it a 250 spine. I am going tomorrow to the shop and measure for length. Hopefully I can get away with a 30 or 31" but it may have to be 32 which could weaken it some. We'll see what happens.

Thanks again,
Wade

Sent from my HTC U11 using Tapatalk
 
You should be totally fine with a .250 spine arrow. I'm guessing your total arrow weight (TAW) will come in around 430-440 grains without any added weight. That's a plenty heavy arrow. I would be surprised if you can't get them tune and group well.
 
I think these will work. Only 20 yards but I never got a group of five like that with my old bow that was way too short. Now I have to dial in at 60 to get my new sight dialed in completely. I sure can tell that proper form makes a huge difference and that you can't have good form with a bow that doesn't fit.
84dd443f7b62015e4110cf89ad5a276c.jpg


Sent from my HTC U11 using Tapatalk
 
I'm 30" draw, 70lbs. I shoot a 500 grain arrow total length about 31". I've got one pin zero'd at 30 yards, and it's about 2.5" high at 20 yards, 1.5" high at 10 yards. Past 30 I start to drop pretty hard, but have an adjustable pin set at longer distances on a dial, and never shoot past 30 unless I've got a calm deer at a known distance with plenty of time to shoot.

Keep in mind with a longer heavier arrow (especially with high FOC), you may need to stay with longer fletching to steer it properly.

For several years, I was shooting 600 grain arrows (seven deer, 6 pass throughs and one spine shot that completely severed spine) up until last season. I made the switch to the 500 grain. This allowed me to shoot one pin for a much larger range of distances. I shot three deer (two pass throughs and one spine shot that completely severed spine). One of these broke front leg on shot side, still passed through.

At that length and draw weight, you're throwing a baseball bat at them regardless. 500 grains seemed to be the sweet spot for speed/momentum/practicality for my shooting. I think you'll find the same within +-50 grains.

As far as spine, .300 or under will be fine with moderate FOC. .250 would be my choice regardless, but should handle high FOC if you go that route (I would).
 
Longer fletching on a higher FOC arrow is only needed if the spine is wrong. If you can't shoot a bare shaft right with your fletched arrows, your spine is off.
 
You must log in or register to reply here.
Back
Top