Need some bow tuning help-plez

[Luckyned]

Hi All!

  My buddy let me hold on to his 50lb Montanna longbow when he moved to Florida. I decided I would give it a fair shake and test it out as it has a more 'traditional' grip then mine. I've run into trouble because all my arrows appear to be too heavily spined and I really don't know what range of brace height is recommended. How much spine weight might I weaken to if I add point weight from 125 to 145?  5 lbs? I don't mind buying more arrows but I never did learn about point weights and how much it might break spine. Anyone like to recommend wooden arrow shafting favorite. Sorry, lots of questions but..I have lots of questions.  

[Smallwood]

Bill, what arrow are u shooting now? for a right handed shooter, your nock on a bare shaft should kick right if it's stiff and left if it's weak.
you could jump on up to a 175 or 200 grn point and see if there if a noticeable difference in arrow flight with your fletched arrows if you don't want to bare shaft test them. If your shooting wood arrows i believe the formula is +/- 5#s of arrow spine for every inch longer (+) or shorter (-) than a 28" draw length.

[Luckyned]

Hi SmallWood,

  I am currently tuning with un-cut arrow shafts (31")purchased for my original bow that are 50-55 spined at 28". They do kick nock-right which leads me to believe they are too stiff BUT..WOW! 31 inches long and are still too stiff for a 50 lb bow when my 55lb bow shoots them wonderfully? Can't be. Now, I'm not sure what spine group to order. I think I may just order 45-50 and then test over.

[jhansen]

Ned,
How heavy a point are you using now?  How close to center is the riser cut on the bow that shoots the arrows well?  The shelf on the Montana isn't even near center and that makes it more finicky about spine.  I agree that something is wrong here but I think more info is needed.  One thought that comes to mind is that if an arrow is too much too weak it can act like it is too stiff.  On release, the increasing pressure on the shaft causes the middle to bend away from the riser.  The nock end is bending toward the riser.  The shaft then flexes back the other way and the nock end swings away as it passes the riser.  A too weak shaft can bend more than it should and the tail of the shaft strikes the riser before it can swing away causing a false stiff indication.  (Gee, I sure hope that all made sense.)  Might try cutting one shaft back 1/2" at a time and see if things get better.

John

[Luckyned]

jhansen Sir,

   I do believe you are correct in both of your thoughts (without better info from me) My Martin does have a closer cut and starting way out at 31" on the bareshaft testing might be throwing a reverse tail of the truth. I'm currently practicing with an unknown shaft which I assume is a Douglas Fir spined at 55 and cut to about 30" with a 135 grain Grizzly. They fly straight so I'm working on my "comeback" form with 3 of these til I fiqure out what shaft and what spine I hope will work.
  I must confess to actually sucking at tuning a bow by any means but by tinkering til "it" goes where I want and looks good getting there. I think my strange form/style might get in the way of bareshaft testing. I shoot with a killer cant and can't undo it. I can shoot with a slight cant if I force an unusual shot but it is not my normal shot. Without video..let's put it this way.. if I'm laying in the dirt to avoid detection..I'm kinda close to my form. (lol)

[aromakr]

I don't know how anyone can tell if your spine is correct or not, when we don't know how long your draw is!  A 31" shaft will spine 35-39 if its 50-54@28".If you draw 28" and use a 28" arrow then 50-54 spine shafts should work fine, with up to 150 gr points. You need to remember that for every inch longer than 28" you will loose 5# in spine. By the way I would start you brace height at between 6 1/2- 7"
Bob

[Luckyned]

Thank you all for posting. I'll be referring back to your posts while I try to setup for this Montanna 50 lb bow. I feel alittle wimpy after watching a Howard Hill dvd where he is using a 90lb bow! I'd break my shoulder if I tried that bow weight. I've always shot a 28" arrow but I'm trying to refine it so a broadhead touches my knuckle this time. I'm starting from scratch with this bow, my other bow seems more forgiving with spine and thanks to you all, know I understand why. I'll report back when I get my new shafts up and running.