400 spine Carbon vs 400 spine Alloy?

Mav617

Member
Hi,

Shooting my Lightspeed 3Ds tonight for the first time and they were all over the place. It was as if they were too light for the bow (Rytera Bullet X compound at 54lb approx on finger release). They were all going right, yet my 2117 Gamegetter Alloys shot OK. Same length arrows, 27.5".

Both the carbons and alloys are rated as '400', so how come the carbons shoot so poorly. I seem to remember shooting 500 Lightspeeds (26") OK with this set up so what's going on?

Can anyone help before I Ebay my Lightspeed 3Ds?
 
G

GuardianAngel

Guest
My only guess is that the LS are lighter than the alloys therefore less forgiving on a bad release. Heavy arrows are less critical.

Sent from my GT-I9100 using Forum Runner
 

Exarcher

Active member
Were you shooting indoors or out ? What temperature were you shooting in ??

It's been flipping cold the last few days...... consider the effect of temperature on the 'stiffness' of carbon and aluminium.
 

Stash

New member
The .400 is a "static" spine. Both arrows will bend the same amount under a given weight, but the carbon will spring back faster, and behave like a much stiffer alloy arrow in actual performance. The vibration period of a very light carbon arrow is much faster than a very heavy aluminum arrow.

You probably will need a .500 carbon to behave like a .400 aluminum.
 

Mav617

Member
Thanks Stash,

So shooting the carbons indoors on a cold night at 25 yards might not be the best way to gauge them then? I have some shorter 500's that behave impeccably but as I'm looking to increase my poundage on the bow in summer I thought the 400's would be better. Should I hang onto them in case I get to 60lb and see if they then start to shoot okay? Every bow chart I consult seems to suggest that a 55lb hard cam compound with a finger release needs a 400 spine Lightspeed.

Ah, well, there are on Ebay now, item # 320842116800
 

jerryRTD

Well-known member
Charts will get you into the ball park. You need to bareshaft tune, until you do that you are wasting your time trying to judge if your arrows are any good. Bareshaft tuning will allow you to consider altering such things as point weight arrow lenght and so on, you have to find out what is happening to your arrows when they are shot.
 

Mav617

Member
Thanks Jerry. I trusted the archery shop to help me specify the arrows, can't believe they're so far out. I have shot them once before reasonably well thinking about it and since then have adjusted the arrow rest and re-fletched these with ep23 vanes. Wonder if I've cocked up the fletching somehow but I used a jig and to my eyes they look fine.
 

jerryRTD

Well-known member
Thanks Jerry. I trusted the archery shop to help me specify the arrows, can't believe they're so far out. I have shot them once before reasonably well thinking about it and since then have adjusted the arrow rest and re-fletched these with ep23 vanes. Wonder if I've cocked up the fletching somehow but I used a jig and to my eyes they look fine.
They are not that far out but you need to bare shaft tune for your bow and your loose and until you do that you are not going to know what is going on.
 
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