Spine suggestions?

[Ippus]

I haven't put a spine tester together yet, but I'm about to start straightening some wild rose shoot shafts and I wonder if you can make a recommendation on what kind of spine I should be looking for. The shoots are in a variety of thicknesses.

My bow is 71" ntn, pulls 28#, maybe a little less, at my draw length of 30". No cutout, not centershot at all. I'm thinking 100gr target points for now, self nocks. Would 31" be long enough? I've never tried to match arrows before...

[Pappy]

Probably about 35/40 lb. spine, with the 30 inch draw, the spine is usually measured at 28 inches, so adding 2 more inches will reduce the spine by roughly 10lbs.[ never done Rose so may differ] but this formula works for most shafts with a 125 field point. The 100 will make the shaft a bit stiffer. Of course if you are making you own tester you can make it to test anyway you like, I am referring to a commercial bought tester. I would just cut some at 31 or maybe longer32/33 being sure they are pretty stiff so as not to break when shot/bare shaft and see how it flies, then work from that, if you are right hand shooter the back of the arrow will hit left in the target if it is to weak, then you will need to shorten it or go with heaver shafting, if it hits tail right in the target it is stiff and you can add length or weight of tip or scrape it down a bit to get it to hit straight into the target. Then when you get one doing what you want, test and make the others match as close as you can. Lots of trouble and time but well worth the effort before you go fletching a bunch of arrows that won't fly good from the bow. Hope this helps a little.
 Pappy