Spine Recommendation

[redraider94]

Hoping to get some help from all of you who are smarter than me....

Mathews Z7 - 28" Draw
#70 bow but cranked down all the way I am measuring around 66.10 pounds
Shooting Victory RIP 300 Spine - 29.5" shaft / 57 grain insert / 100 gr head

Wanting to move to a heavier overall arrow and increase FOC to 18-19

Looking at BE Rampage 300 Spine (8.7 GPI)
125 Head
101 gr insert
29" bare shaft
66 Pound Draw at 28"
Nock is 7gr
Fletching 7 gr x 3 = 21 gr

Puts me at 506 gr Total weight (right where I want)
Puts me at 19.55 FOC (slightly higher than I want but fine with it)

Question: TAP Pro says my ideal spine should be .243 which I think is material from the .300 I would be shooting. Has the program lost it's mind here and I should go with a .300 spine or go with .250 spine.

Going to 250 spine and all else equal due to the increase in GPI:
564 gr Total Weight (heavier than I want)
17.54 (Better than where I am at now but a little lower than my goal of 18)

Anyone have any other programs to check and how much confidence does everyone have in those programs spine recommendations?

Thanks!

[Grady_jones]

Don’t have a program but can tell you from experience.

My arrows are 250 spine black eagle carnivores, Mathews VXR 72 lbs 28.5 inch draw with a 117grain insert and 100 grain tip. The 250s were just a little too stiff I had to buy a top hat for it to tune properly. But they hit like hammers now. I think for your setup 300 spine will be good.

[Fishndude]

Stick with300. Great choice of arrow and components to get high foc