It will all depend on what the setup is. Did you run your setup through their arrow chart to see what arrow it recommended?
www.60xcustomstrings.com

 

According to the draw weight formula, I end up at 88lbs with a 28"'arrow. Shaft selector chart says I'm ok. But if I tighten my limb bolts all the way to 80lbs my adjusted draw weight is 93lbs.....which is outside the recommendation for that arrow. I don't necessarily plan on increasing my draw weight, but I don't want to paint myself into a corner.

 

I guess I'm looking for some real world info. Not just manufacturer chart recommendations.

 

The recommended spines are just that recommended. They have to be safe and lower their recommendations for safety issues. I shoot 70 lbs 28" draw and shoot 250s. If you run the numbers it says I'm way underspined, but the bow tunes to it and shoots bullets.

 

That's good news. Have you shot fixed blade BH?

 

I only shoot expandables, maybe just buy one or two and make sure they tune first.

 

I am shooting Maxima Reds 350s at 29 inches with ~90 Mathews Safari. I was assured by my local dealer that they would be fine based on the chart. I was a little worried the arrow is slightly less than 5 grains per pound. The arrow weighs 409 grains and hits 356 fps.

 

The draw weight range is BS. Maybe 90lbs at like a 24" DL ... Lol

It's still just a 350 spine arrow.

 

Wish this was facebook I'd hit the like button. My husband used to shoot those till he finally came to his senses LOL Easton all the way for us.

 

Winmag, your adjusted draw weight is probably over 100lbs. Are they grouping well? What about with fixed broadheads?

 

So far I am grouping petty well, even pie pan at 60 yards. That said I think I should get stiffer heavier arrows, I am clearly over... Draves Archery has used 380 grain blue streak arrow: https://www.youtube.com/watch?v=V5WPcsr3ohA

 

Watched that video. He was grouping those arrows well at what I'm assuming was 20 yds. Surprisingly quiet too. Curious to see how it would group at 30 or 40. Or with BH's.

 

I predict fixed broadheads will impact way right of the fieldtips...

 

Out of the 90 safari? Wouldn't surprise me. I shot maxima blue streak 350's out of my 75lb insanity and they were too weak. Bare shaft impact was 8-12" right at 20yds

 

If your going to shoot heavy dw shoot the appropriate spine. My .02

 

So in you're opinion, is a max red 350 too weak for a 75lb insanity....27" draw, 28" arrow?

 

According to OT2 your way weak. Should be using a 300 spine arrow

 

That's typical for OT2

 

Ya I've got a 125 gr point, so that's not helping the spine any.

 

Real world
I tuned 350's at 64 lb 29.75" DL @28" carbon to carbon out of spyder 34 with 100 gr tips
any more was too weak. I could tell a difference in group sizes with 25 more grains up front from being too weak.

A bare shaft will tune if you have DL correct with a weak spine but down range your group size will open up.

The Z5 cams are hard and aggressive, I have mine tweaked to be around 60% letoff

The Red's are 0.342 spine at 28"

OT2 tells me I need 0.332 which is real close.

Since my initial tune I have cranked bow up to 70 lbs, same arrows just a 65 gr tip

shooting ok but not as tight.

I really wish carbon Express made a 300 spine arrow for it's longer draw length shooters and hunters
the charts calculations on the reds must be followed, when I did I was almost off the charts but definitely need a 350 not a 250 as I was directed by some people around. Do the math if you are middle of chart, OK if not go for stiffer spine

 

You could shoot the 250s and be fine. You put the numbers in and it says that it's way underspined. But they will tune and shoot good! I was instructed to this but a very well know archery in the industry. Next arrows will be 250s instead of 350s

 

Yes CE doesn't have enough 300 spine options. The maxima hunters are just heavier than I'm looking for, I think 9.7gpi. I'd prefer a 125 gr point to help my FOC, especially with a lighten nock. Gold tip velocity pros in 300 spine are like 8.7 gpi or sumthin. That's an option.

 

My 350 maxima reds tuned great out of my hoyt rx-7 80lbs 26.5". I tried the maxima sables this year in a 350 in hopes to relocate more weight from the shaft to the front of the arrow seeing they have a lighter gpi than the maxima reds. I was a bit skeptical that they would still be stiff enough. I was still able to get them to paper tune but it was much harder. My tears were not very consistent until i got it perfectly tuned. Thats often a sign of an underspined arrow. I also had an arrow deflect bad upon hitting a deer, which I've heard a weak spine can make more likely because the arrow bends more upon impact