Bulzeye

Cigar time for this man.

10 point shooter

Speaking of spine. How do you tell the spine of an arrow? Is the lower number stiffer or the higher number? I finally took my trykon 80 lb. to the pro shop and he worked on it for hours the harness was way out, that's why I couldn't get it to paper tune.He got it close with fixing that, butit was still out a little. He finally tried a stiffer arrow the epic 2 300. I was shooting the gold tip pro hunter 7595 w/camo, at 26-1/2" blazer vanes 125 grain point. Whisker biscuit. I thought that was about as stiff has I could get.

ijimmy

Excellent pictures , you've answered your own question and that of many others , spine is critical , too weak will give you fits , as will very stiff .

phil 5oh

I think spine is more critical with aluminum than with carbon arrows. If you've seen high speed video, aluminum takes longer to correct itself (straighten). Over-spined carbon arrows seem much more forgiving than over-spined aluminum. PSE 300s with 65 gr points shoot fine for me at 60#. 2613s with 145 gr points did not shoot as well from the same bow. Both arrows have 4" vanes.

Paul L Mohr

As much as I hate to put down my beloved aluminums I will give you that one. From my experience I have had better luck shooting overly stiff carbons than I have aluminums. But still the proper spine is always better. I think it might be because lighter carbons tend to have better FOC than the heavier aluminums.

I will tell you a few other things that make a difference as well, release type, whether you shoot with a string loop or not and the type of rest you use. I have actually found that drop a ways are more critical of spine, not less. And they require a slightly different spine than a prong type rest. My Bodoodle set up properly is much more forgiving of spine than any of my drop a ways.

At least that is what I found in my shooting.

Paul

Straightarrow

Just so people know, if your spine is a bit weak or a bit strong, you can still tune the arrow to shoot a broadhead well, but you will need to adjust center shot accordingly. The problem arises when some are a bit weak and some are a tad stiff. Now, you have arrows going left and right. Center shot adjustment has no positive effect on both types at the same time. This is why I choose to shoot all my arrows a bit stiff. Spine tolerances are not yet good enough on most carbons to try and hit it on the nose.

AllenRead

Paul,
Very good post, Thank you!

What type of release and rest are you using?

I tried a similar test with CXL2's recently. I left them full length so that they should be way underspined. OT2 shows that27" is correct length for my set up. Both fletched and unfletched were hitting the same POI at 20 and 30 yards. This was with a hinge release and a launcher blade rest.

One reason that I'm not getting different POI's is that my bow is a shoot through, Nitrous X system. Maybe the lack of the torque of a cable guard affects the results?

I agree that properly spined arrows are the best for accuracy and forgiveness. However, I haven't figured out a shooting test for carbon arrowsto prove that the spine is correct or what adjustments are needed.

Finger shooters have this bare shaft planing test, what do release shooters use to adjust spine?

Thanks for posting this!

BGfisher

Paul,

I think this also shows that grossly underspined arrows (1816's) will still group well with target points. They just might fly ugly getting to the target. It also shows you were shooting pretty consistently.

Good post.

Paul L Mohr

When I shot those I was using a fletcher 3-D release, the big ugly green one, with a string loop. The rest I currently have on my bow is a Drop Zone. I did have a bodoodle on it and I feel it was a bit more forgiving. I couldn't get it to work with the blazers though. If I index the arrow to get the fletching to clear my rest, one hits my harness.

When I switch back to feathers I will go back to the bodoodle. That rest shoots AWSOME, even with a slight amount of fletching contact with my feathers.

I agree blade rests are pretty forgiving as well. If I were to set up a target bow that is what I would shoot. I may look into getting one for my girlfriends bow. She already has a nice GFK on it, just need to get a blade is all.

It's amazing how little things can actually affect the spine of an arrow, like where you nock, the type of rest you use and the type of release.

Paul

CAJUNBOWHNTR

Paul are you left handed? I thought a bare shaft right indicated weak spine?


Thanks,
CB