Arrow question

[Red Sparky]

Here is the question before posting on Bowsight or Archery Talk and getting an argument going. I would rather have the argument here . My draw length is 30", draw weight 68# with a release. I am shooting a 29 1/4" arrow, measured from where the point screws in to where the nock meets string. Bow has been tuned to where broad heads and field point group together and I am shooting 100 grain Slick Trick Mags. The arrows are Carbon Express Mayhem Hunters with a .347 spine. I plan on going to chrono it at the bow shop to find out exactly how fast it is but I remember around 280 fps. I also plan on getting an actual arrow weight while I am there.

 

When I shoot, especially with a lighted nock at long distance, it appears the tail is slightly corkscrewing. It appears the nock is traveling in about an 1"-2" diameter circle. When I say long distance I mean 60 yards and not 100. I did spin test all my broad heads and it happens with every arrow and not just one or two.

 

Now I am thinking of changing arrows to Easton Axis or FMJ. Reading the Easton chart on arrow spine I am right on the cusp of 340 and 300 spine. I am going to increase arrow length a bit to use the Exodus head which would push me more towards the 300 spine.

 

So now the question: Do you think if I go to a 300 spine and increase the head to 125 grains I will get rid of the corkscrew or should I just leave it alone? When I shoot my broad heads at 60 yards I am still getting about 1/2-2/3 of the arrow penetrating the target before it stops.

[Redman]

Well according to my archer's advantage program, the mayhem is extremely weak spine for your setup (30 draw , 68 pounds). Not knowing your brace height or bow could impact it a little....

 

 

The Easton Axis 300 or the FMJ 300 are optimum spine. Not all spines are created equal

 

I would suggest changing your arrows to a stronger spine.....adding more weight will only make your current arrow weaker

 

Sorry I am going out of town this morning for a few days and won/'t be able to help (if you where to provide your bow and brace height)

 

good luck really think your arrow is too weak. I have used the Axis and the FMJ, the FMJ are heavier and will be about 10FPS slower and they do not hold up well if you miss a target... I now use the Axis and they are tough arrows and less costly.

[WHT_MTNMAN]

+1. Sounds like you need a stiffer spine.

[Maverick351]

What bow are you shooting? Your cams can also help determine what spine you need. Smooth cams can go weaker spines where as aggressive cams need stiffer.

[QhunterAZ]

Try a Bare shaft tune, paper tune.possible a walk back tune. Do the broadhead hit exactly right with your field points? If they do hit the same spots your fine. If you want to be sure slap on a wide blade fixed broad head large muzzy perhaps of the same weight. And if they are still hitting the same your tune is good. Weak or stiff spines could effect it. Do you use helical fletchings? Use a whiskerbiscut?

[AverageJoe]

This can be common if shooting helical vanes. I shoot straight vanes for a few different reasons.

 

It can be hard to tell without paper tuning if your arrow is actually corkscrewing or if it is an optical illusion brought about be various shadows and helical vanes. When i shot helical vanes i always thought my arrow was corkscrewing. I went through countless hours trying to remedy it. The end result was i went to straight vanes instead of helical and realized my arrow was perfectly straight the whole time and my mind was playing tricks on me.

 

If your arrow is actually corkscrewing, shoot bare shafts through paper and look for a left or right tear and go from there. If no tear is seen shoot a vaned arrow and check again. If all looks well on paper most likely you are experiencing an optical illusion.

[AverageJoe]

Also if you increase spine but add a heavier broadhead, you will be close to where you were with a .340 spine and 100 gn broadhead. I think your spine is fine. I have found spine to be much smaller impact on arrow flight than people think, unless you are severely underspined but at that point you are in a danger zone. .340 spine mayhems with 100 gn broadheads shooting 280 fps is just fine.

[HuntHarder]

300's the end....

[Red Sparky]

Bow is a Hoyt Charger, brace height 6 3/4". Blazer straight vanes. I was thinking I was under spined with the arrows. I did have a WB on it but changed to a QAD hunter drop away rest so re-tuned it. I also sprayed my vanes and rear arrow with talcum powder so I know I don't have any clearance issues. Started with paper then walk back, then broad head but I didn't do the bare shaft tune. When I first started broad head tuning I found out the nock loop was showing high with broad heads, perfect left to right with field points just about 2" low, so I just slowly raised the new rest until field points and broad heads were hitting the same spot at all yardages. When I say same spot the bow will shoot better than I can but they are within my group circle at that distance. 20 yards I strive for a group < 2", 30 < 3", 40 < 4", 50 < 5", 60 < 6".

 

I am thinking if I get the 300 spine and it is too stiff with the 100 grain heads I would add 125 grains to weaken it some.

[GotBowAz]

Agree with stiffer spine, you are also taking away from front of center weight with your lighted knocks as they weigh a bit more than standard knocks so increase your FOC and your arrows will react and correct quicker. So yes a heavier head weight would go a long way.

[Codywhi]

Check out the gold tip F.A.C.T system little weighted incerts you can screw on an off to play with the FOC jumping to a bigger broadhead can really cause loss of penetration when you get into some of these huge cutting diameters. stiffer spine for sure as said earlier, I would recommend just buying the archers advantage program it's worth it's weight in gold.