Hi, new to site and have a question regarding proper arrow spine. I'm shooting a Ross Carnivore at 60#, 27.5" draw length, drop away rest, string has a peep with tube on it, D loop if it matters? My current arrows are GT 5575 hunters at 28.5" with 100 grain tips and 4" vanes. When I shoot at 30-40 yards I notice my arrows are porpoising and impact the target coming up.
When I shot these arrows from my Diamond Rock at 60#'s they shot fine. Could they be over spined for the Ross?
Ross calls the cams on the Carnivore Hybrid would that mean they are hard, medium, or soft?

Any advice would be great.

Thanks Mike

Hi, new to site and have a question regarding proper arrow spine. I'm shooting a Ross Carnivore at 60#, 27.5" draw length, drop away rest, string has a peep with tube on it, D loop if it matters? My current arrows are GT 5575 hunters at 28.5" with 100 grain tips and 4" vanes. When I shoot at 30-40 yards I notice my arrows are porpoising and impact the target coming up.
When I shot these arrows from my Diamond Rock at 60#'s they shot fine. Could they be over spined for the Ross?
Ross calls the cams on the Carnivore Hybrid would that mean they are hard, medium, or soft?

Any advice would be great.

Thanks Mike

Sounds like you may have a weak arrow. Did you paper tune it? How did it tear?

Yes it was paper tuned it was tearing to the left, only took the shop guy about six shots till what appeared to be perfect bullet holes. It only porpoises when I shoot at 30-40 outside, 20 outside it shoots fine. I'm baffled at what would cause this and can't make it back to the shop for at least a couple of weeks due to work schedule.

What I would tell is that the shop guy and you may have different grip pressure and the bow is tuned for him and my not be tuned for you. You need to shoot the bow thru paper ans see if there is a tear on a bullet hole. This is my Humble Opinion.

That sounds like your nocking point may be a hair high or low, this would cause the porpoising from 30-40 but not necessarily 20....another thing that might cause this would be if your bow is out of tiller just a tad....just to clarify, your arrows are flexing with an up-and-down motion as they approach the target, right? I call side-to-side motion during arrow flight "minnowing"...
I dont know if those suggestions will help, but they've worked for me in the past.....

Thanks for the replies. I'll shoot it through paper and see if there is any difference, and do some research to see what "tiller" is and check it.

I must have got lucky with the Rock because it shot great, just aggravated my shoulder. :(