Spine help

[okcaveman]

I am shooting a osage longbow that is 48# @ 27". My draw is 29", and I am shooting 175gr heads.  From my ineffectual toying around with stu calculator I am getting that I would need shafts spined at around 35 pounds. Does this seem correct? The bow is not centercut. I am looking to shoot POC arrows as well.

Any help is appreciated because arrows are expensive lol

[Orion]

Is this a self-bow or glass laminated bow? Does the bow have any shelf at all?  If it is glass laminated and has a shelf, I'd say you need a shaft in the 60-65# range. Drop that 5# if it's a self bow.  At 29 inches, you're probably drawing 53-54#.  That, plus the heavy point necessitates a heavier spine.  If its a selfbow and there's no shelf at all, 50-55# would probably work.  If it is a selfbow, I hope it's a long one, i.e., at least 64-66 inches.  Any shorter than that, and you're really stressing the limbs with a 29-inch draw.  If so, it's not a matter of if it will fail, but when.

[okcaveman]

It is a self bow and has no shelf. It is 66 n2n. Thanks for the assistance orion

[Art B]

For a 53# arrow 29" long, you would need a spine of 58# to start with. Add 15# for that 175 gr point. Probably going to need at least a 30" arrow so that would add another 10# of spine. But you can subtract that for a wide handle. Probably between 70-75 is where I would start. You can alway sand these things down if they're to heavy, or leave a little longer to reduce spine. Get 'em to light and you'll have to go down in point weight to make 'em work. Good luck.....Art

[okcaveman]

Thanks art. Man this is a tricky thing to figure out