Arrow Tuning w/selfbow

[Howard S.]

I'm shooting an osage selfbow for the first time. Just built my first set of arrows and need some help with tuning. I drawing this bow to about 42 lbs. I started with cedar shafts spined at 30 - 35lbs. I have them basicly full length (31" to BOP) with 125gr points. At 10 yds they hit right where I'm looking and bare shafts are grouping right with them. At 15 yds. I'm hitting left consistently with the feathered shafts and the bare shafts are everywhere. I'm thinking that I'm underspined but don't really know. Any help or suggestions would be appreciated.
Howard

[K Harris]

It sounds like your bow and the one I shoot are similar.  Mine shoots well with 40-45 cut to 29" with a 125 grain head.  I have a 27" draw, and I use a fast-flight string on mine.  The 42-43 spine arrows seem to be the best, but the 40's and even an odd 46 fly well.  I would say you are correct about your arrows being underspined.

[4est trekker]

What length of feathers are your arrows fletched with?  You'll have a hard time tuning anything under 5" with a selfbow, particularly the further from center your shot window is.  This is why a lot of guys chuck them out the window, because tuning an arrow takes a bit more time with a selfbow (at least in my observations).  Also, add a little helical twist to the fletches if they don't already have some.

I shoot the same poundage as you at 26" and prefer a 35# spined shaft.  If you find that they are indeed too heavy (in spine, that is), cut them down an inch at a time if you've got the length to spare.  That'll increase their effective spine weight.  However, if you're hitting left, that's a sign of a stiff shaft.  You can increase the point weight to 150 grains and see if that helps.  That will decrease the effective spine weight.  

But, I'd start with the fletching if they're under 5" and/or applied without helix. Hope that helps  

[tim roberts]

When tuning bows, I have found this to be the best place to go for directions;
 http://www.bpbows.com/modules/content/index.php?id=23

Its quick and very easy to understand!
Hope this helps,
Thanks,

[4est trekker]

Just remember...a selfbow is a different beast.  Many of the rules that apply to fiberglass bows don't always pertain to selfbows.  And...try not to overthink it.  Try some things, even if they go against the grain or intuition.  When they shoot straight and hit true, keep that set-up.  That's the beauty of a selfbow (other than looks)  

[Jim now in Kentucky]

No matter what the spine, if your arrows are all near the same spine and flying all over, YOU are the problem.

The bow will  do the same thing every time if you do. If the arrows are the same, they will all do the same thing if you do.

If they are all flying differently, either they are not alike, or you are not consistent.

These are 48# spined arrows from a 37# black locust self bow at 20 yards.
 

[K Harris]

Howard, I sent you a PM.

[Howard S.]

I'm sure that I am probably at least part of the problem, re. consistency.  The arrows are fletched with 5 1/2" helical shield cut feathers.  Any thoughts on brace height and it's impact.  I had a suggestion of bracing between 7 & 7 3/4" to the BACK of the bow which ends up giving me about a 6" brace height.  I thought of adding heavier points but don't know where to get heavier point for 5/16 arrows.  

Howard

[Art B]

I answered you on your other thread Howard.

You're not going to need a heavier point. That'll only make matters worse. Grossly underspined arrows can impact the target left OR right. Cut an arrow back to 28" BOP and start from there. That'll start you out with a 30-35# arrow. Right now, with your arrow 31" long, it's dynamic spine is 20-25#.

If, after you shorten your arrows, and you're still having problems, they'll be new problems you'll have to deal with. But get your arrows right first. Good luck........Art