Overspined?

[Jonathan_S]

I am new to this...

Everybody tells me I should be overspined but my arrows are flying straight, I've only shot to 30 yards so far with field points but I can't imagine a problem developing beyond 30?

Will a problem become more apparent when I put on broadheads?

[Instinct]

From what i gathered is its good to be over spined than under. Not sure how much over spined you can be over but the second you throw on a broadhead when your under your arrow will be flying erratic.
Maybe few other peeps will chime in with better details.

[coyotecrazy]

I would rather be over spines then under. There are several charts available to make sure your arrows are matched for your bow spine wise. Broad heads change flight for me, especially with further distances. Look up and check the chart, I think Easton has one online you can use. Check the manufacturer web site of the arrows you use.

[Rainier10]

According to the shop and the shaft selectors I am overspined also but have no problems all the way out to 90 yards.  I think underspined is definately worse than overspined.

[Jellymon]

You may not see the arrows fishtailing, and even if they are you can still be accurate with field points. Now too stiff is defiantly better than weak.
To get any real answers we need to know your poundage, draw length, arrow length, arrow spine, and point weight.

[bowjunkie]

over better than under
shoot what you have if it is working for you keep it
on the chart i am overspined but i have an agressive cam
i shoot slick tricks took my deer at 75 yrds and my elk ant 80yrds with no problems

just remember if it is working for you stay with it

[Jonathan_S]

You may not see the arrows fishtailing, and even if they are you can still be accurate with field points. Now too stiff is defiantly better than weak.
To get any real answers we need to know your poundage, draw length, arrow length, arrow spine, and point weight.

#60 Bear Encounter which advertises 310 IBO
27" draw length
28" arrows
arrows are 340
125 point weight

[Instinct]

I say ditch the 125 and go w/ 100gr, but i basically run the same set up

[Jonathan_S]

Yeah my arrows are a smidge over 400 grains right now so I'll probably go down to 100, at least to test it out.  I'm far away from purchasing any hunting points.

[RadSav]

There are benefits and disadvantages to going stiff on spine. 

The benefit is that a stiff spined arrow will have a more consistant dynamic spine than one flexing more.  Less need to orient spline to a single position on all arrows to bring groupings together.  When shooting out of a machine it is the superior arrow.

The down side to shooting too stiff an arrow is it's forgiveness or the lack there of. The dampening of initial inertia and the optimizing of archers paradox within each materials behavior allows for some human mistakes without the effect showing flight issues to such an extreme as a stiffer arrow.  An optimized spine will also help points of different configuration and slightly different weights group closer together.  The optimized spine will also tend to impact much more in line with the center line of force in the bow.  Meaning in general your pins will be more above the center of arrow before launch (much more of an issue when shooting barebow than with sights).

One should always have a good aggressive helical to their fletching for improved flight and forgiveness in all weather conditions.  If shooting a stiff spine that helical holds even greater importance.

I do not think I saw where you mentioned the brand and model of arrow you are using.  Also the type of fletching used.  If I didn't miss something that would make it almost impossible to know whether switching to a 100 grain broadhead would be advisable or not.  The 125 grain head is definitely not hurting anything at all.  And seeing as how you are already over spined I would probably still recommend the 125 even if it is not necessary for good FOC.

I agree with posts above...it is much better to be over spined than underspined.  Much safer too

Optimum spine for the squaw is around a 600 spine though she shoots a 500 spine for weight and durability while hunting.  When she has two good eyes she is an elk killing machine out to 60 yards.  Broadheads and field points will never group together for her at 500 spine.  But none of the deer, elk or antelope have seemed to care

[owmygulay]

Do not switch to the 100 grain tip that was recommended above. It will increase your spine. What arrows and Fletch? Anything on the spring besides d-loop and peep? I will run the numbers through a program I have and see what it says for you.

[Jonathan_S]

Beman MFX Bone Collector Arrows with 2" Twister Vanes is what I'm shooting.

[Jonathan_S]

Thanks to everyone for their input.  I think I'll stay with the heavier point for now.  Like RadSav said, I should have a more helical fletch and that is what I'll do next.  I really like that setup so far.  My groups aren't airtight yet but that's probably mostly operator error.

It seems that I have better groups at 40 than 20 which is weird but for hunting purposes, I'll be happy with it.

[RadSav]

It seems that I have better groups at 40 than 20 which is weird but for hunting purposes, I'll be happy with it.

That's not uncommon if your set-up is not perfectly tuned and your offset/helical is minimal.  Spend a little more time getting it tuned and that should go away.

Also, many have the habit of trying to watch there arrows in flight at 20 yards whereas at longer range the arrow comes up into vision on it's own.  If you find yourself watching the arrow you'll probably watch it miss more often than not.

[turkeyfeather]

Do not switch to the 100 grain tip that was recommended above. It will increase your spine. What arrows and Fletch? Anything on the spring besides d-loop and peep? I will run the numbers through a program I have and see what it says for you.

Could you expain this more as to why you think the 125's are better. The reason I ask is cause when I bought a new bow a couple years ago(also a Bear) it was recommended that I switch from the 125's I was using to 100's. Don't know if the 125's would have been better or worse, but at 40 yards I'm insude of 2-3 inches with the 100's.

[RG]

Here's the question you need to ask yourself.   Are my shots going where I want them to and are my arrows flying the way I want them to?  If the answer is yes then what else matters?   I had and archery shop for 7 years, went to the PSE dealer tech school and tuned a ton of bows.  Here's what I learned.  If it works don't fix it!

[Gamblin Guy]

Here's the question you need to ask yourself.   Are my shots going where I want them to and are my arrows flying the way I want them to?  If the answer is yes then what else matters?   I had and archery shop for 7 years, went to the PSE dealer tech school and tuned a ton of bows.  Here's what I learned.  If it works don't fix it!

What he said....and when I really screwed something up on my bow I could bribe you with a little duck jerky to fix it.   

[Gamblin Guy]

Todd will chime in with the numbers from his program when he sees this, like everyone said though, over spined is better than under.  If they are flying good with broadheads and grouping well then dont mess with it. 

Here's another resource too...

[RG]

Here's the question you need to ask yourself.   Are my shots going where I want them to and are my arrows flying the way I want them to?  If the answer is yes then what else matters?   I had and archery shop for 7 years, went to the PSE dealer tech school and tuned a ton of bows.  Here's what I learned.  If it works don't fix it!

What he said....and when I really screwed something up on my bow I could bribe you with a little duck jerky to fix it.   

Hey!  We had a bunch of people over yesterday.  The duck jerky was the hit of the party.  No BB's in anybody's teeth either.

[jechicdr]

I shoot a similar setup but with a 70# draw so I was fairly accurately spined with 125 grain broadheads (though ever so slightly over spined, the 150 broadheads made a more perfect spine according to the software while also giving me a higher front of center which should translate into better down range accuracy.  The larger surface on the broadheads of course means bow has to be well tuned and technique has to be optimal.  I think the best benefit to having the perfect spine, is that your field tips and broadheads will hit nearly the same area when shot from center shot.

[RG]

I am a big proponent of a little overspine on a hunting arrow.  An arrow always follows its point and it's the job of the fletching to stabilize it and keep it on track to the target.  Broadheads put wings on the point which makes it harder to stabilize so, as the shaft flexes, it wants to begin following the tip.  Overspining a little minimizes the flex and gives, in my experience, the most consistent flight shot to shot.  Underspined is a disaster on hunting arrows, I've done it and watched in wonder as the arrows snaked their way downrange after flying perfectly with field points.


http://www.bing.com/videos/search?q=video+arrow+flight&view=detail&mid=59F75A790821104C7F5D59F75A790821104C7F5D&first=0&qpvt=video+arrow+flight

[Jonathan_S]

To wrap this thread up, in case someone is reading it for tidbits in the future.

I went to the shop last night and paper tuned, got all the fishtailing out of my flight and ended up getting my nock point moved up as well and the arrows are flying excellently now - through paper and my groups are tighter under 30 yards.  Took about 20 shots to get it right.

I tried a few shots with a 100 grain point just to see the difference - in this case made the problem far worse.  With a 125 grain point they shoot much better and my FOC is 13.3% for what it's worth.

BOW:  60 lb Bear Encounter RTH
Draw Length:  27"
Arrow Length:  28"
Arrow: Easton ST Excel Carbon 340 2" Blazer Vanes, offset (exchanged the Beman MFX Bone Collector 340)

Thanks again everyone for your help.

It sounds like typically 340 would be too stiff for this setup however...

Here's the question you need to ask yourself.   Are my shots going where I want them to and are my arrows flying the way I want them to?  If the answer is yes then what else matters?   I had and archery shop for 7 years, went to the PSE dealer tech school and tuned a ton of bows.  Here's what I learned.  If it works don't fix it!

following this idea obliges me to stick with what's working.

If I have problems when I put broadheads on, I'll examine the arrow selection again.  For now though it would seem that the bow is properly tuned.
Here's the question you need to ask yourself.   Are my shots going where I want them to and are my arrows flying the way I want them to?  If the answer is yes then what else matters?   I had and archery shop for 7 years, went to the PSE dealer tech school and tuned a ton of bows.  Here's what I learned.  If it works don't fix it!