Shooting the spine out an arrow?

[Hunting_Oregon]

I am having trouble getting my bow to tune with fixed blade broadheads. My local archery shop said that i more than likely have shot the spine out of my arrows. I shoot Gold Tip Pierce Platinum 250, 525 grains, 80lbs, 28.5" draw. I shoot a lot and these Gold tips never seem to break so I still am shooting the same 2 dozen I bought awhile ago. If shooting the spine out is a real thing is there a way I can check if my arrows are toast?

 

[Rob5589]

Shot the spine out of an arrow? That's a new one on me. Easiest way to know is check them with a spine checker.

I'd bet that your bow is out of tune vs the spine has been shot out.

 

[PurpleDriver]

dumb question, but was the bow in tune before with these arrows?

I’m with Rob, it’s more likely something in the bow than the arrow. I also have never heard of a shot out spine.

 

[Bump79]

I'd be surprised if it was the arrow - but with micro arrows I wouldn't be as surprised. I'd look at tune over your arrow. If it's consistently hitting off regardless of arrow then I'd look at the bow.

A standard diameter arrow gets more of it's rigidity from it's geometry (larger diameter). While a micro arrow is gaining more of it's rigidity (spine) from the carbon & thicker walls. With a high modulus carbon arrow it was a thinner wall making it depend even more on the material. So if the material starts to wear out then the spine would be out. That said - I've never shot out my X-Impacts or Element Storms.

 

[Hunting_Oregon]

Yes it shot fix blades perfectly last season. I have owned the bow since 2015 and have shot fix blades every hunting season. This year they are not flying great and after 2 hours in the shop getting it worked on it still won't shoot them straight. That is when they said it was because I shot the spine out of my arrows. I have never heard that before and at basically $300 a dozen fully setup I'm not in a hurry to buy more.

 

[OR Archer]

what shop told you that? Lol you can’t shoot the spine out of an arrow.
Also what bow is it? When’s the last time you had the strings changed?

 

[5MilesBack]

Find someone with a RAM spine tester and check them. They can check straightness too. I'd be more inclined to think that straightness consistency had gotten worse. I did that with a couple sets of well used arrows and my GT Kinetic XT 200's were literally all over the place with consistency for both spine and straightness. In some cases straightness was reading .007 or higher (supposed to be .003" new), and spine had a wide range across the dozen. I could tell the difference which is why I took them in in the first place.

 

[WoodBow]

I would not recommend that you continue going to that shop.

 

[Mighty Mouse]

Are you getting consistent broadhead groups? If so, the arrows are fine, you just need to adjust your bow to get your broadhead group to align with your field point group.

If field points are grouping consistently but broadheads are not, I would first put the arrows on a spinner and check for bent inserts or broadheads. If everything looks straight, you could test for insufficient arrow spine by reducing draw weight to see if broadhead grouping improves. If it does, that could indicate you're underspined. I suppose it's possible for an arrow's spine to weaken with repeated shooting. I'm not sure if this concept translates exactly to carbon fiber, but other materials are known to experience "fatigue" (gradual weakening) with cyclical application of stress. Another possible cause of poor broadhead grouping could be insufficient fletching. If you've downsized your vanes or upsized your broadhead, that could be the culprit.

 

[Beendare]

I have never seen that...and have some carbons that are many years old.

A good strategy is to take all of the critical measurements when the Bow is tuned…so that you can check for string and cable stretch And know how to get it back to the sweet spot settings. Plus, mark the cams to check rollover.

If you do that, you know right away not only that its out of tune but what to do to get it back.

FWIW, it might be time to start making your own arrows…my Accmos shafts are $36/doz plus components I’m all in at about $50/ doz.

 

[Tilzbow]

If you didnt shoot much, or at all, over the winter and picked up your bow and started shooting in the spring it’s possible the arrows and the bow are just fine. Your grip, or some or form related change you’re not aware of, could be the cause.

As far as arrows losing spine, I once had a tire shop tell me lug nuts are a one time use item and want to charge me for 32 new ones when I bought new tires for a 3 year old truck. I didn’t go back to that shop…..

 

[5MilesBack]

I once had a tire shop tell me lug nuts are a one time use item and want to charge me for 32 new ones when I bought new tires for a 3 year old truck. I didn’t go back to that shop…..

In 1999 I asked a salesman at a Ford dealer what the exact differences were between their new F-250 and F-350 Super Duties. He said "Oh, the F-350 is a lot more powerful than the F-250"......LOL. Idiots abound.

 

[GuyinIdaho]

Never heard of shooting the spine out of an arrow, especially all 12 of your arrows at the same time.... I have had the same arrows for 3 years and they still shoot great. Might need to start replacing fletchings, inserts, and collars. Would also be good to check the weights of each arrow to verify they are consistent. Could be the bow too, string maybe?
same fixed blade broadhead as you were shooting before? I had grouping issues with a certain fixed blade and thought it was my bow but other broadheads group fine.

 

[Billy Goat]

I can remember years ago talk of shooting the spine out of arrows, mostly indoor shafts. I don't know that I ever measured it and found a variation after (x) number of shots.


I do think older carbon shafts are a lot different than modern shafts. Many had memory, like they would hold a bend. Beman was terrible for it. Leave arrows in a quiver in a bow in a bowcase and the nock end gets pushed down, those arrows would stay bent for a long time.


I doubt with GT you shot the spine out, infact I think that's a claim they make about spine not being able to be shot out.


I'm not super familiar with carbon life cycle/lifespan, however I wonder if this missing sub deal is a factor of exceeding life cycle of the carbon fiber resin.

 

[Tilzbow]

Years ago I actually bought a broadhead target that would cause the “spine to be shot out”. I can’t remember the name of it, but it was super heavy (nearly 80# at 30” x 30”) and made with carpet glue or some other similar material that was real dense, contained sand in the material and would thin the front 6” to 8” of carbon shafts to the point broadheads wouldn’t shoot well after a few dozen shots. That target ended up in the landfill after a few weeks.

Edit: I had to check, the name of the target was “The Blob”…. Many swore by the target but it was worse than worthless IMO.

 

[Beendare]

I doubt this is the OP's problem...probably bow tuning.

I don't think the finish on the US made arrows is as good as it used to be.
Something changed 5-10 years ago and the finish on the Easton shafts wears faster. L to R, Axis, Accmos, Easton Trad from 3 rivers [these are the worst]

It might be they can't use the good solvent based finishes...not sure but the Chinese ones have a good finish that wears well.

 

[ElkArcher918]

I am having trouble getting my bow to tune with fixed blade broadheads. My local archery shop said that i more than likely have shot the spine out of my arrows. I shoot Gold Tip Pierce Platinum 250, 525 grains, 80lbs, 28.5" draw. I shoot a lot and these Gold tips never seem to break so I still am shooting the same 2 dozen I bought awhile ago. If shooting the spine out is a real thing is there a way I can check if my arrows are toast?

Wow, you shot the spine out of the arrows? That's a new one that I've never heard of, visually observed, or experienced. It's likely the bow is out of tune or your shooting technique is flawed, i.e. torquing the snot out of the bow. Being slightly over or under spined shouldn't make a monumental difference where hunting arrows shoot. Check arrow straightness with an arrow spinner especially if you shoot fixed BHs. I would look for another reputable bow shop and check arrow spine with a spine tester for your piece of mind.

 

[5MilesBack]

Edit: I had to check, the name of the target was “The Blob”…. Many swore by the target but it was worse than worthless IMO.

I still have my Blob that I bought in 2008. It's great. I use it for BH tuning.

 

[kodiakfisher]

So if will offer this, I also have a super heavy duty foam cabelas target. Impossible to pull a field point out with my bare hands. Anyways my #10 broadhead 150 grain cutthroat SS single bevel arrow was always my practice broadhead and earlier this year it shot amazing at 80yds, I have hit the dirt a few times with it now practicing out to 100yds. Fast forward after lots more shooting and suddenly this arrow will not shoot straight 10 inches left at 80yds. Field points all great still. So I decided to shoot all the other broadheads back at home 40yds, they all shot perfectly fine (into my soft target).d I grabbed the #10 practice broadhead and at 40yds I'm 5 inches to the left....I removed the broadhead and put it on my #12 arrow now I am 5 inches low, remove broadhead put it on my #14 arrow and perfect at 40yds. For reference my Mathews VX3 with my arrows that I built will consistently shoot sub MOA usually 3inches @40 and just today my very best group ever was 5 arrows 6" at 75yds. Axis 340 28inches 70lbs draw. I know that I'm leaning just a touch under spined but I put 200gr points on instead of 150 and noticed no changes in my group leading me to believe last year my spine was fine.

 

[Blockcaver]

I wonder if Hunting Oregon got his arrow/tune problem solved? Would be nice to get a wrap on this year old thread containing a lot of speculation on potential causes and "shot out spine".

I am having trouble getting my bow to tune with fixed blade broadheads. My local archery shop said that i more than likely have shot the spine out of my arrows. I shoot Gold Tip Pierce Platinum 250, 525 grains, 80lbs, 28.5" draw. I shoot a lot and these Gold tips never seem to break so I still am shooting the same 2 dozen I bought awhile ago. If shooting the spine out is a real thing is there a way I can check if my arrows are toast?