I posted earlier about wanting to shoot wood arrows our of my new-to-me 70" Two Tracks Echo 64@28 (drawn to 29.5)
To that end, I ordered a 3Rivers Hunter Arrow Test Kit cut BOP 31", fletched and with 190gn point up front.
The kit had 8 arrows.
2 - 65-70 spine, weight 570gn and 624gn
2 - 70-75 spine, weight 632gn and 604gn
2 - 75-80 spine, weight 672gn and 618gn
2 - 80-85 spine, weight 620gn and 636gn
With these arrows (minus the 570 gn, 65-70), I headed to the range. To my surprise, with the exception of a few flyers the arrows consistently grouped together (within my poor shooting abilities).
This makes me think that I could add some more weight out front on the 80-85 spine, and be set with the right spine and the weight of arrow I'm looking for.
Yep. Most bows are quite spine tolerant. They'll shoot a range of spines to the bull, and look good doing it, if we do our part.
Try the test again with broadheads. Any spine problems will jump out. Fletched arrows with field points are very for giving; bhs not so much.
With a centershot recurve you can get away with a wide spine range - especially overspined.
QuoteOriginally posted by Stumpkiller:
With a centershot recurve you can get away with a wide spine range - especially overspined.
That's what surprised me, the Echo is a straight limbed, not centershot longbow.
I'll have to try broadheads like gringol suggested.
Your bow will only have one dynamic spine that flies well no matter how much centershot a bow has. Fletched arrows won't mask a poor match as you get better.
True, there is only one theoretically optimal spine for a given bow/arrow combination, but few of us have form good enough to find it.
Luckily, most bows will shoot a range of spines WELL, particularly overspined arrows, as Stumpkiller notes. For example, I can vary the spine of my arrows by 15# on my ACS bows, and get arrow flight that's perfect to the naked eye and hit what I'm shooting at. That's good enough for me.
Take a look at the "Old School" tuning thread for lots more examples. I've been shooting sticks for more than 50 years and have seldom had a problem getting extremely good arrow flight, and I'm sure some my arrows weren't perfectly matched to the bow. I'm not nocking the latest spine calculator/formula. I think it's an excellent tool, but we managed to get good arrow flight long before that tool was developed.