Which Spine

Joined
Mar 23, 2012
Messages
655
Location
Western WI
I am looking at getting some black eagle arrows and need some advice on what the best spine is for me. According to the spine chart I should get a 350 spine but I want an arrow that is around 500 grains.

Would that weight weaken the spine too much and should I go to a 300 spine?

For reference I currently shoot a 28.5" CE Maxima Hunters in a 350 spine at 419 grains from Mathews Z7 at 63lbs.

Thanks you for any advice you can give me.
 

Trial153

WKR
Joined
Oct 28, 2014
Messages
8,225
Location
NY
I think you can probably get by putting another 50 grains up front in the insert on the 350's . You can also cut them back a bit if you had the room with your rest/ broadhead combination.
 

sim22mie

Lil-Rokslider
Joined
Jun 25, 2016
Messages
102
Location
NE
Would also depend on point weight. Have you put your current setup through a chrono?
 

Tony Trietch

Part Time Bow Hiker
Staff member
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Jul 28, 2013
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2,127
Location
Northern MI, USA
Depends on a lot of variables.

If you add weight to front of arrow it will weaken the spine, opposite if you add it to the rear of shaft.

Get yourself On Target 2 or Advantage archery computer programs. The program will not only help pinpoint exactly what yo are seeking but teach you the how and why.
 

bcopley1116

Lil-Rokslider
Joined
Oct 9, 2016
Messages
170
Location
West Virginia
I shoot Spartan 250's that 518 grains. My draw length is 27.5 and I'm shooting around #82. It has been a perfect setup for me.
 
OP
tim tarras
Joined
Mar 23, 2012
Messages
655
Location
Western WI
My draw length is 28". Below would be the approximate weights of the completed arrows in the different spines of the two arrows I am looking at.

Spartan 300 9 GPI
Spartan 350 8 GPI
Carnivore 300 8.5 GPI
Carnivore 350 7.5 GPI
Fletches (4 at 6 grains)
24
24
24
24
4" Wrap in front of vanes
4
4
4
4
Nocturnals Nocks
20
20
20
20
Arrow weight at 28.5"
256.5
228
242
214
Broadhead
125
125
125
125
Inserts
26
26
42
42
added weight
60
75
50
75
Total
515.5
502
507
504
 

Brendan

WKR
Joined
Aug 27, 2013
Messages
3,875
Location
Massachusetts
I would run one of the 350 spine arrows with that setup. Checking the spartan 350, if you cut the arrow down to 26.5" you're on the stiff side of "green" spine using OT2, arrow weight of 486 gr using all other specs you listed. Expect arrow speeds under 250 FPS with that setup.

Here's OT2. Like Tony said - owning a copy can be very helpful.

d26e2fd681780657d64082b3630c3888.png
 
Last edited:
Joined
Jul 23, 2013
Messages
1,260
I think you should def go with the 350. That z7 probably has more of a 315fps ibo at 28-28.5 inches not 330. So your gonna be plenty stiff.


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