Am I underspined?

[Elk830]

Hi all! I wanted to get your input on whether my arrows are under or overspined. My Obsession Turmoil RZis currently pulling 69lbs, 28.5 in draw length, and IBO of 350. My arrows are 28.75 inches carbon to carbon GT Hunter XTs in 300 spine, 3 blazer vanes, regular nocks, and a 12.5-grain aluminum insert. My question comes down to whether I should use a 125 or 150 grain head. My total arrow weight is 460 with 150 grains and 435 with 125 grains. For elk and other big game should I use the 125, 150, or go to 250 spine arrows to get above 500 grains?

 

[MaxHenderson]

It looks like with 100 grain heads you’re probably fine, but anything higher I might want to bump up a spine.


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[208meateater]

Have you shot through paper and paper tuned your bow? Your tear can indicate if your arrows are too stiff or weak.

 

[Elk830]

Have you shot through paper and paper tuned your bow? Your tear can indicate if your arrows are too stiff or weak.

I have shot through paper and they hit the same. After shooting the 150s and 125s out to 60 the 150s were consistently getting tighter groups. Also, I love your profile picture.

 

[Beendare]

The easy way to find out is tune. If you can't get it to tune....take 2 turns off of your limb bolts and try again.

 

[208meateater]

If your getting bullet holes with both the 125s and 150s, I would use whatever your bow seems to shoot the best. Sounds like your 150s will work out the best for you if they are grouping better. I believe arrow placement trumps arrow weight. I have been fortunate enough to take home big game animals with an arrow as light as 375 up to 550 grains.

 

[WhatToHunt]

If your getting bullet holes with both the 125s and 150s, I would use whatever your bow seems to shoot the best. Sounds like your 150s will work out the best for you if they are grouping better. I believe arrow placement trumps arrow weight. I have been fortunate enough to take home big game animals with an arrow as light as 375 up to 550 grains.

I think it's a balance between placement and weight and finding the right mix of each. Same reason most people wouldn't hunt big game with a .22 even though they might get good placement with it.

 

[Rob5589]

If it tunes and flies well, you're good. For reference, I shoot basically the exact arrow as you but with 160 total up front, 65lbs @ 30.5" and it tunes and flies beautifully.

 

[Hoot]

I have shot through paper and they hit the same. After shooting the 150s and 125s out to 60 the 150s were consistently getting tighter groups. Also, I love your profile picture.

There's your answer...