Spine to suit 75lb

[Wodez]

Hi archers
I am considering getting a new bow in 75 pound with IBO 342fps.
I’m Wanting to confirm what spine I should be using. My current arrows are 300 spine cut to 29 with 125grain heads and I hope to just continue using them. They are victory vforce gamers.
The victory spine calculator shows 300 spine is fine, even if I use 150grain heads. But most other spine charts say 250 spine for 125grain.

I would like the option of using 150grain heads and still be on the safe side but not a deal breaker.

 

[Rob5589]

May as well try them since you have them. But I'd guess your going to need a .250.

 

[Billy Goat]

I think that's the heaviest shaft that they make in that series, so they aren't going to recommend something stiffer. Could be those arrows are actually stiffer than they are labeled as well. I think a true 300 spine at 29" is going to be difficult. I was running 75# @ 28.5 on shorter shafts and went to a 250. I have gravitated towards using a heavier spine and it makes the tuning easier.

If you have them you can try, not going to hurt anything. The spine charts are what's recommended, but it's all starting points. Generally I think for field archery you can go lighter, hunting go heavier on the spine selection.

 

[5MilesBack]

I shoot almost 33" draw at 75lbs with 30" arrows and 125's and I shoot 300's, 250's, and 200's and the bow tunes up great with all of them.

 

[OR Archer]

They’ll work fine. If you were going to add extra weight up front then you would need to cut them shorter or increase the spine

 

[PhillyB]

I shoot the same setup .... 75 lbs.
I have had good luck with .250 and extra weight at the end to reduce stiffness (125g broadhead, 50g insert & lighted nocks)
I have also had good luck with a .300 spine arrow with less weight on the end to increase stiffness (100g broadhead, no insert and standard nocks)

Overall, I prefer the heavier, stiffer arrow for a number of reasons.

 

[Beendare]

Lots of problems when you are under spined;
trying to get BH's to fly and it amplifies your form errors.

Its no problem bowhunting over spined.

So why chance it?

 

[Wodez]

Lots of problems when you are under spined;
trying to get BH's to fly and it amplifies your form errors.

Its no problem bowhunting over spined.

So why chance it?

That’s made the decision easy. 250 it is.
the vforce don’t seem to come in 250 so I’ll have to shop around for a new hunting arrow brand

 

[chadcharb]

That’s made the decision easy. 250 it is.
the vforce don’t seem to come in 250 so I’ll have to shop around for a new hunting arrow brand

Get some black eagle rampages if you want a .204. For the money I don't think you'll get a better arrow and they definitely have them in a 250 spine. If you want .166 check out the x-impact.

 

[stubblejumper]

I've shot 29.5 300s at 75lb for a number of years.

I have always kept what Beendare said in the back of my mind, but when it is time to buy another set, there are no 250s in stock, so I keep doing what I do.

 

[MightyWhitey]

Might consider grizzlystik. They make a 240 spine and sell two arrow test packs so you could choose another spine as well to test with. And if you end up buying a dozen they deduct your test pack price from the dozen. I shoot the 240 out of my 80# 29.5” draw with 315g up front, but I had to cut em pretty short to get them stiff enough

 

[Beendare]

That’s made the decision easy. 250 it is.
the vforce don’t seem to come in 250 so I’ll have to shop around for a new hunting arrow brand

Good call.

The vast majority of tuning problems I see is with guys that cut the charts tooclose on spine.

Arrow with a BH for hunting needs a tad more spine than target/ FP’s. Tune is more critical with a BH too with blades....and just more stuff on the front of your arrow.

Then add that the stiffer spine makes for a more durable hunting arrow it makes for an easy decision.

 

[Jimbob]

I used a 28" Axis 260 with 50 grain brass insert, 30 grn collar and 100 grain head in my 75 lbs 29" Mathews this year.