I am currently revisiting a bow that has been a royal pain to tune. It is an Osage self bow 42# at 28" draw (I only pull 25") It has an arrow shelf, but it is not cut out at all. Here is what I have been shooting. Arrows are 5/16 shafts, at 20-30# spine. They are 29.25" long from throat of the self nock to the back of the point (100 grain). When I shoot, the arrow flight looks pretty good, no left/right waggle, but they appear to consistently drift to the left. Isn't this an indication of stiffness? In the target, the nock end appears to be angled to the left, or to put it another way, it looks like the point is striking at an angle to the right, which I thinks indicates weak spine. I have tried arrows as short as 27" with spine up to 50# and all show so stiff, they will not shoot off the bow without literally turning sideways. I am perplexed! I don't think it is merely a question of form as other bows I have don't show these tendencies.
Sam,
What about increasing the point weight-125, 145, 160, etc.??? How heavy are the arrows? For me really heavy arrows show weak, too light can show stiff???
If you don't shoot that bow much, the arrows impacting left might just be a function of your brain not adjusting the hold correctly. If you shoot instinctively, not lining up the arrow on the target, holding the bow as you would a bow cut more to center actually points the arrow to the left, and that's where it will go.
On the other hand, if you do have the arrow in your line of sight, your brain should be lining it up on the target, and a left impact would indicate a too stiff spine, unless, of course, it's a false stiff caused by a too soft spine glancing off the bow side plate. A brace height that's too low can cause the same thing. I suggest raising the brace height and adding about 10# of spine weight, which should put you right about at the bow weight at your draw length.
Keep in mind, too, that a very light bow and arrow is very sensitive to any errors in form. Good luck.
Yes, as Jerry stated. Also, a slight pluck at release, especially with a light bow and no cut out shelf and the arrow will go left ( if rightie).
ChuckC
O.K. I will play around with brace height and possibly point weight. Unfortunately, my form can be at issue. I sometimes pluck the string. In fact, one of the reasons I want to get this light bow dialed in is so I can work on form with a bow that is very easy to draw and hold. Thanks for the comments.