Technical carbon arrow Question

Discussion in 'Bowhunting' started by ShutUpNFish, Sep 9, 2007.

  1. ShutUpNFish

    ShutUpNFish FishBum

    Okay, my buddy and I were shooting last night, and he noticed that my arrows were flying funny when I was shooting.

    First I'll describe my set-up and then I'll explain my thoughts, then maybe some of you may have suggestions on what the problem may be.

    I'm shooting a Hoyt MagnaTec: 65lb draw weight with a 31" draw length. The arrows are Gold Tip XT 5575 arrows (27") with 100 gr. tips. 3 - 4" vane fletchings The total weight of my arrows are around 369 gr. including all components. The bow shoots approx. 269 to 275 fps. When I went on the following site to calculate what minimum weight arrow I should be shooting, it looked as if I may need more weight, but I don't know for sure. I also was not sure what they meant by "ENERGY" cam vs. "SPEED" cam? My bow is a single cam bow...Hoyt's Versa Cam. I plugged the mumbers in for Energy cam. heres the link...

    What my arrow is doing: The arrows group well and hit where I'm aiming, but the ass end of the arrow seems to fling around some, causing the arrows to enter the target at an angle instead of straight in. It gets worse as I increase my shooting distances.

    My thoughts: I'm thinking that the arrows need to be heavier or I need a stiffer spined arrow? If I add weight, does it matter where I add the weight? Front or rear or is front my only option? Or should I try a heavier arrow all together. I think heavier in the front may just make the back end fling even more. I know I'll probably just end up going to the archery shop for assistance, but wanted to hear some feedback from you guys first.

    OOps...I left out that I'm using a NAP drop away rest.

    Thanks in Advance Guys!
  2. GPtimes2

    GPtimes2 Oh Deer

    Man, you remind how technical it is to get the right spine, arrow wieght, tip wieght, etc...
    First I would recomend that you post you delimma in the tuning forum on This is the second time I recomended this sight today for someone here. I like this sight, but it doesn't get the amount of expertise that archerytalk does, as you will see, and I hope my direction helps you.
    As to some of what I can tell you. It used to be popular in traditional archery (not sure it still is) for your arrow to bend away from the riser as it passed by. Thats were the weak spine helped (so the arrow didn't hit it). If I remember correctly, it's called the archers paradox. It's been a while since I thought of such things, so I may not be right on some things. People still use spine stifness for compounds and find that they have to incorperate that into the tunning process. You will need to select the right arrows first (you could already have then). Then you go from there to get the length, tip wieght, fletching, maybe wraps, and knock wieght all set up to get you in a proper FOC (forward of center) range. Proper FOC will give you good arrow fight. This is were you determine if you want to add or remove wieght in the front or rear. Adding wieght to the front will increase FOC and make a weak spine weaker. Adding wieght to the rear will decrease FOC and make the spine act weaker (not actually change the spine).
    Once you have your arrows were you want them, you can tune the bow. Most people paper tune (shoot through paper at close range, 5 or 10 feet). The way the paper is cut tells you witch way to adjust the arrow rest and knock point. That will get you shooting well, and arrows flying straight. If you want to go farther then you get into walkback group tuning.
    As to cam ratings, a variety of terms are used. They may be refered to as smooth, fast, speed, energy, etc... It helps the softwere pic what info to give you (in your case). It has to do with the draw cycle. How aggresive it is. How long the valley is. Does it break over easy (smooth) or hard (fast) etc...
    Something about tuning and shooting in general- If what is happening is continuously repeatable, you can get good groups even with improper tuning and even wrong arrows.
    OK, I strained my brain and probably left some things out, but you will learn all about it in you future research. It may sound worse that it is, but I hope this helps!:)

  3. I would start with tuning your bow. It is lengthy, but the basics are covered here: .

    The arrows are a little light for your setup ( in weight, not spine- because they are so short). The lighter the projectile and faster it flies, the more unstable it will be (generally - if all other things are constant). Longer arrows are also more stable in flight. It also causes more damage to your bow. Considering your draw length/and draw wt. Hoyt would most likely recommend a heavier arrow. their web site may provide more info. You may actually void the bow's warranty if you go outiside their guidelines.

    Another thing to consider- have you noticed some of your vanes being damaged? If you are shooting with a fall away rest, the timing of the fall away must be "tuned" also, believe it or not. If the rest falls too slowly, the vanes will contact the rest and cause the arrow to wobble in flight. If the rest is falling too fast, the arrow will not have enough support to guide it during the initial part of the launch, and the flight will be erratic.

    good luck, and good hunting.
  4. Fishpro

    Fishpro Northcoast Madman

    Are you shooting an overdraw? The other guys have given great advice, but I want to know how you are shooting a 27" arrow out a 31"draw?:confused: your arows are fine as far as weight goes(minimum would be 325gr.), but you should be shooting a longer arrow.
  5. ShutUpNFish: I ran your setup through a couple of archery programs (On Target and TAP). I assumed you have a Magnatec ZR as opposed to the XT model. You're both underspined and have a low F.O.C. It proved quite a challenge to find an arrow both adequate in spine and an FOC over 10%. Assuming your drawlength is ATA (ie, arrow is even with the front of the bow), you can be as short as 29" and the arrow (more importantly, the broadhead) will still be over the riser. A couple matches for your setup would be:
    1. Beman ICS Hunters 300's. 29". 125grain point. 3 4"feathers or Blazer vanes.
    2. Carbon Express CX 400's. 29". 125 grain point. 3 4" feathers or Blazers.

    They'll be a bit heavier and the FOC on both of those is a touch over 11%. Hope I helped some.:!
  6. ShutUpNFish

    ShutUpNFish FishBum

    Thanks doe girl....all this information is good stuff! I'll be taking the bow to get tuned this weekend.....anyway, to answer your Q Fishpro....yes, the Magnatec came with a built in overdraw which allows me to shoot shorter arrows. However, it seems that I may have to go a little heavier and a little longer. Thanks all!!
  7. I have th esame bow. I started with beeman ics hunter, 30 inch, arrows and 100 grain heads, I was shooting 68lbs and a 29 draw length. It was dead nutz. I needed new arrows and the guy at the proshop suggested i go with lighter and shorter gold tips, 27 inch. My arrows were all over the place and I had everything tuned and retuned and switched rests from whisker to quick tune and back several times until I was about out of arrows from losing them all in the back yard as I was having trouble hitting the target. I went back to a heavier longer arrow, same beemans, and all of a sudden my now slower bow was alot more accurate for me.

    Lesson Learned: 20 feet per second don't mean a thing to a deer, although it may to a proshop salesman, as long as you can put it in the boiler room!!
  8. Before you mess with tuning your bow,try some different arrows,something as similar as possible,my guess is your arrows are a batch that doesnt measure up,I ran into this last year with easton axis that I couldnt believe was the problem but I fletched up 6 I had from previous year and my problems went away.After putting them on a gram scale and a arrow straightner only 3 of the dozen was even close.Just a thought,shadowalker:(