Arrow spine help

[ElkHunter5]

I'm planning on buying some FMJ Injexion arrows and can't decide if I should get the 330 or 400 spine.

My setup is...
Hoyt Carbon Spyder 30
70lbs
27" draw
Smackdown Pro rest.
Not sure on arrow length but probably 27.5 - 28" length.

Thanks.

 

[RosinBag]

What weight up front...just from your first description I would go 330, but I prefer slightly stiff on my hunting arrows.

 

[ElkHunter5]

I was planning on using a 100 grain head and the standard 20 grn insert.

 

[charvey9]

I shoot the 330's out of the same bow at 71.5lbs, 28.5" draw, 28" arrow at 280fps. Finished weight is 455 with a 100gr tip, which I think is about perfect.

I do think if you went with a 27" arrow, you are right on the border of being able to shoot a 400 spine if you are looking for a lighter/faster setup.

Get 3 of each and see which one tunes best..

 

[BackcountryMT]

You're definitely on the border. I would up your head weight to 125's and go up to the 330's.

 

[RockBridge]

I shoot the same draw length and weight, and arrow length as you ElkHunter5. I recently switched from a 400 spine Gold Tip with 100g point, to a 340 spine Easton Axis with a 125g point. The results have been really good for me.

 

[OR Archer]

400s. That arrow cut at 27" is more than stiff for your set up.

 

[ElkHunter5]

I really appreciate the help. It sounds like I could go either way depending on how long I cut my arrows or how much weight I add to the front. For hunting larger game like elk, would it be advantageous to go with the heavier .330 spine or would the .400 give plenty of penetration?

 

[BackcountryMT]

I really appreciate the help. It sounds like I could go either way depending on how long I cut my arrows or how much weight I add to the front. For hunting larger game like elk, would it be advantageous to go with the heavier .330 spine or would the .400 give plenty of penetration?

Generally, a heavier arrow will out penetrate and lighter arrow. Also, a stiffer arrow will penetrate better as there is less flex on impact.

On my personal setup I am shooting a Goldtip XT7595 (.340") cut at 26.5". I have a 50grn brass weight behind the insert and 125 grains up front. This is yielding a very slightly stiff arrow from a 66# Agenda 6@27".

 

[charvey9]

I really appreciate the help. It sounds like I could go either way depending on how long I cut my arrows or how much weight I add to the front. For hunting larger game like elk, would it be advantageous to go with the heavier .330 spine or would the .400 give plenty of penetration?

You'll probably get a 50/50 split on answers. Only 32gr difference between the shafts at that length. I'm guessing 8-10fps. If shot placement is good, no worries on penetration with either arrow. I lean toward the speed and would take the 400, but really no wrong answer. A heavier arrow will be more forgiving though, so depends on your personal preferences.

 

[Coyote Commander]

You're definitely on the border. I would up your head weight to 125's and go up to the 330's.

What this guy said.

Ill take heavy and "slow" any day of the week.

 

[Tilzbow]

I'd go with stiffer spine. It'll give you more options on length and point weight. It's nearly impossible to go too stiff with a drop away rest.

 

[charvey9]

There are lots of opinions on the weight vs. speed debate, but here is my take.

An ethical hunter should practice, and know he can place the arrow where it needs to be to make a kill while excercising good shot selection. That said, the goal in arrow selction would be one that shoots accurately and penetrates through the animal when the above statement is met. Penetration is excellent, but there are no bonus points for burying your arrow 15" into the ground after it passes through your target. A pass through is a pass through. If you need an arrow that can shoot through a shoulder blade because you don't always shoot so good, go back to step 1. Penetration is not a good reason to take a bad shot.

Once you have an arrow that will shoot accurately and pass through a target (momentum and K/E calculations can help with this) with a good ethical shot, look for speed. Flat trajectory is down played a lot, and in many places maybe it isn't a factor. From my personal experience, the 3D course I practice at has a lot of hunting type shots. One in particular is 49 yards, and in the summer months when leaves filled in and branches start to droop you are pretty much shooting through a tunnel. With a little trial and error, I've figured out that a bow needs to shoot 280 to avoid the leaves and branches in that "tunnel" and make the shot. The areas I hunt are similarly thick, and shots have potential to be obstructed by both under and overbrush. I think its all about finding a balance between speed and penetration.

 

[Coyote Commander]

There are lots of opinions on the weight vs. speed debate, but here is my take.

An ethical hunter should practice, and know he can place the arrow where it needs to be to make a kill while excercising good shot selection. That said, the goal in arrow selction would be one that shoots accurately and penetrates through the animal when the above statement is met. Penetration is excellent, but there are no bonus points for burying your arrow 15" into the ground after it passes through your target. A pass through is a pass through. If you need an arrow that can shoot through a shoulder blade because you don't always shoot so good, go back to step 1. Penetration is not a good reason to take a bad shot.

Once you have an arrow that will shoot accurately and pass through a target (momentum and K/E calculations can help with this) with a good ethical shot, look for speed. Flat trajectory is down played a lot, and in many places maybe it isn't a factor. From my personal experience, the 3D course I practice at has a lot of hunting type shots. One in particular is 49 yards, and in the summer months when leaves filled in and branches start to droop you are pretty much shooting through a tunnel. With a little trial and error, I've figured out that a bow needs to shoot 280 to avoid the leaves and branches in that "tunnel" and make the shot. The areas I hunt are similarly thick, and shots have potential to be obstructed by both under and overbrush. I think its all about finding a balance between speed and penetration.

I agree with you 100%.

But I'll add, no matter how good you are, how careful you are, shoot enough critters and you WILL have a bad hit. Since guts are soft and squishy and easy to blow through, I'm gonna error on the "heavy and slow" side to blow through bone.