Wood Spine Question

[frankwright]

I have some tapered fir arrows that are spined 55-60.
Tapered Fir Shafts
I bought them to shoot from a 52# HH longbow. They group very tightly to the left indicating too heavy a spine.

Yet they shoot perfectly from a 45# Zipper recurve.

Does indicate they are too heavy to bend around the longbow since they work fine with a center cut recurve?

Thanks!

[macbow]

That sounds about right.

[AWPForester]

yep.  And that recueve has more zip making the spine requirements heavier.  God Bless

[Fletcher]

Not so much the "zip" as how deep the shelf is cut.  Put on some heavier field points and see if it helps.

I find Hill bows to generally shoot a spine a bit under draw weight with a 28" arrow and 125 gr point.

[Pat B]

The taper of the shaft can reduce the effective spine by up to 10#. A tapered shaft "gets around" the bow better than a parallel shaft.

[snag]

I taper shafts for guys and find that the spine decreases only 1-2 lbs.  But the clearance is made slightly better. As Fletcher says a recurve that has a more center cut shelf will be more forgiving. With HH style bows it is more important to get a spine weight that will allow the arrow to bend around the handle.