am i underspined?

[earlmarne]

OT2 software says my optimal spine is .2657.im shooting a strothers moxie maxed at 73 lbs with a 30 inch draw.my arrows are .300 spine beman ics hunters with 125 grain tips goin 280 fps.ive been playin around with my new rest n doin some bare shaft tuning.got my fp n bareshaft grouping together out to 40 yards.n even put some paper up at 20 yards n was getting perfect bullet holes.my only issue is my groups have grown alot.a good portion of the time i will scatter all over my bag target.now i understand that i am a big variable here,but my groups that are scattering are shots that feel solid n good.i seem to,most of the time be able to know my shot is off upon release.but recently not so much.n the kicker is i feel like my form is better than ever.everyone tells me its good enough n alla this but i feel like theres something missing.i am capable of 3 n 4 inch groups at 40 yards n i have made them many times in the past month but it seems to have all gone to crap.any advice would be greatly appreciated.

[lokidog]

Have you checked your rest to make sure nothing is out of adjustment and ticking your fletches upon release?

[earlmarne]

well.i just recently put a tt smackdown pro on n it was getting contact on the top of the containment bar due to my rest dropped while i was out in the woods.but now i think im pretty squared away.how would i be able to tell?

[windygorge]

do the bare shaft test.  most accurate way of knowing

[earlmarne]

explain please.i was bare shaft tuning today n my bareshafts were hitting left of my fletched but some minor adjustments n now they r hittin together at 40 yards

[windygorge]

explain please.i was bare shaft tuning today n my bareshafts were hitting left of my fletched but some minor adjustments n now they r hittin together at 40 yards

not sure what your fine adjustments were, but if you are shooting bare and fletched at 40 yards and they are hitting the same, your good.  as long as your arrow is flying true and straight. 
to bare shaft test, i cant remember if hitting left or right.  but start by playing with your poundage.  if you take off poundage and it fixes the problem, then good to go.  if it get worst, then you will need to add poundage, or, shorten your arrow to make it stiffer.  cut 1/4" off each time.  the shortening, or stiffening should correct if you need more spline.  assuming you have something to cut off. 
the absolute best person to talk to is radsav.  that man knows arrows like no other.  give him a pm and he can help you.

[earlmarne]

thank you very much.i get this crap in my head n it just stresses me out to no avail.

[coachcw]

 take your 125's off and put 100's on if your groups tighten up your underspined

[earlmarne]

well that makes sense 2.i think the old lady has 100 grn fp. i cant get by with 100 grain tips though.so if it turns out to be the the case i will have to be buildin a new arrow.i hope i can make these ones work

[coachcw]

remember you need to be at close to 440 grains at 73 lbs

[earlmarne]

understood.im only at 450 now so i aint got much wiggle room unless i find a dif shaft ive got a decent foc right now also n wouldnt be able to get that from the other spines ive found without bn well over 500 grains

[coachcw]

I shoot carbon express 350 maxima hunters with a 30 inch draw at 70 lbs with wraps and 100 grain bh and wraps i'm right at 420 with no spine issue

[RadSav]

Yes, you are under spined.

Yes, you can go to a 100 grain head if you are shooting Blazers or similar, no wrap and the Vibrake insert.  That would still give you a little over 10% FOC.  Gives you about 2 pounds more to work with.  Bad news is you will still be under spined.

No, you are not under spined enough to be effecting your grouping if your bare shaft testing is good to 40 yards.

No, you are not under spined enough to effect your grouping while maintaining perfect form.

1.5 turns backing off your poundage will take you to the 300's optimal spine.



Now you get the question everyone claiming to be 30" draw gets from me.
Q:  Are you 6'3", taller or built like a gorilla?

I would venture to guess you are looking at a form or fit issue and not a spine issue.  I am impressed that you are tuning your bow well enough to get the bare shaft grouping together.  That's nearly impossible to do with a long, weak spined, all carbon arrow.  So I am not worried about your bows tuning, rest tuning, cam timing, limb deflection or the usual Strothers riser flex.

Other questions to narrow it down without watching you would be:
Do the flyers have a consistant location of impact?
Do you shoot with a wrist sling?
Where is the trigger of your release located (finger tip, first knuckle, second knuckle)?
Is your bow hand stiff, tight or relaxed at the grip?
Are you shooting these large groups with bow quiver and target quiver or just one?

[Todd_ID]

Or is it as simple as your NEW bow was tuned perfect, but the string stretched causing new tuning/contact issues?  A tiny bit of lipstick on the edge of each vane will transfer to the contact point on the rest or bow very well, and you can generally tweak either nock alignment or rest timing (length of rest cord) to get rid of the contact. 

Oh, and another  is to use a lipstick that your wife won't be looking for anytime soon: the bright red stuff that she used like elk scent to attract you all those years ago but you haven't seen since the "I do" won't be missed.

[lokidog]

Or is it as simple as your NEW bow was tuned perfect, but the string stretched causing new tuning/contact issues?  A tiny bit of lipstick on the edge of each vane will transfer to the contact point on the rest or bow very well, and you can generally tweak either nock alignment or rest timing (length of rest cord) to get rid of the contact. 

Oh, and another  is to use a lipstick that your wife won't be looking for anytime soon: the bright red stuff that she used like elk scent to attract you all those years ago but you haven't seen since the "I do" won't be missed.

I think lipstick would work better on the rest and see if it shows on the fletches....  just my experience.