Help with Z7 Extreme arrow pattern

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This topic contains 7 replies, has 4 contributors, and was last updated by bow-drawn Bow Drawn 6 months, 3 weeks ago.

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  • September 24, 2013 at 11:37 am #596135 Back to Top REPORT

    toddvy56

    Joined: 3/3/2011
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    Brothers,
    I have had this bow for about 2 years. I have not been able to get the arrow pattern I am looking for.
    I have taken bow to two different Mathews shops -tuned and re-tuned. the bow paper tunes.Still shooting inconsistent. I will never claim to be the best shot in the world but… I am looking for ideas to help.
    For example: shoot six arrows @ 20 3 great 3 random location. I am not heeling the bow(all the time :) )

    Mathews Z7 Xtreme
    63 #
    29 inch draw
    QAD rest
    Beman ics hunters 340 grain
    True Fire Release
    True Glow sight

    Any help? Thoughts?
    THANKS

    September 25, 2013 at 7:38 am #596239 Back to Top REPORT
    mathews-technical
    Mathews Technical


    Joined: 7/16/2013
    Is it always the same three arrows hitting in random locations?
    September 25, 2013 at 9:14 am #596250 Back to Top REPORT
    gjarcher
    gjarcher

    Age: 70
    Joined: 10/3/2006
    Location: Colorado
    View My Bows

    Is it always the same three arrows hitting in random locations?

    Good question … often it is the arrows, not the bow that need to be corrected.

    First, number the arrows.

    Second, shoot each arrow through paper at 5′. Don’t make any changes to the bow, yet. All arrows should have the identical paper tear. Any that are different from the majority, should have the nocks turned until they produce the same tear as the others. If they won’t produce the same tear, they are ‘lemons’, and should be set aside for stump shooting and varmits, etc., and especially not used for broadheads.

    Next, with all arrows checked out and only using the ‘good’ ones, do a walkback tune to  verify centershot setting, but first make sure you set the sight bubble to be level when the bow is plumb.

    Finally, shoot at 30 or 40 yds using a fresh target. Put an X over the hole of any bad shot you know was your fault, only observe the pattern of holes you felt were good shots. If the pattern is taller than wide, then move the nock height down about 1/32″ or the rest up 1/32″. Shoot another fresh target, about 24 shots should be enough (2 of each arrow), and continue to make adjustments until the group is circular. If at any time the pattern is wider than tall, raise the nock height or lower the rest slightly.

    Now you have both the bow tuned and the arrows checked out. From here on pay attention to the outlier arrows, the ones that aren’t in the group with the others. If there are a few that most often are outliers, then it is probably a spine issue … usually they are weaker than the others, and less forgiving. Despite what specs arrow manufacturers advertise, spine consistency and 360º uniformity commonly are not that good, especially with all carbon shafts.

    A homemade spine tester takes a day in the shop and under $50 to make. It is invaluable for sorting and building arrows. {#emotions_dlg.mathews_thumbs_up}

    • This reply was modified 6 months, 3 weeks ago by gjarcher gjarcher.
    September 26, 2013 at 3:37 am #596369 Back to Top REPORT

    toddvy56

    Joined: 3/3/2011
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    Guys,
    thanks for the responses. I am starting the testing process. I have eliminated 4 arrows out of 24 so far. I will have more time to shoot today and tomorrow. I really appreciate the insight. I will post when I have more data. Thanks!!!
    Todd
    September 26, 2013 at 10:31 am #596400 Back to Top REPORT
    gjarcher
    gjarcher

    Age: 70
    Joined: 10/3/2006
    Location: Colorado
    View My Bows
    One other thing … inspect/change the nocks. Nocks get slapped around and are not intended to last forever. Minor deformation of a nock can have huge affect on arrow flight. Nock fit and nock pinch are also important things to check.

    Beman ICS Hunters come with the S-Nock, but any standard ICS nock (.246″) will fit. I recommend the Bohning Signature or Easton Super Nocks because they have a larger throat than most other nocks, are good quality, and are a better fit to the center serving. The nock should snap onto the centerserving but fit loose enough so that it will slide up/down with little or no effort.

    Also, check for nock pinch. With the nock fitted to the string up against the upper D-Loop knot or nock point there should be about 1/16″ gap between the nock and Lower D-Loop knot or nock point or eliminator button/release, etc. When the bow is drawn the string angle will close up the gap. Without a gap, the string will pinch the nock, exerting pressure to lift or twist the nock, causing inconsistent arrow flight.

    September 27, 2013 at 6:54 am #596524 Back to Top REPORT

    toddvy56

    Joined: 3/3/2011
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    More testing:
    I have done more testing. My pattern is taller than wider. All my servings\nock points look good based on the spec you outlined.
    I can not patter in a circular fashion. I checked some of my nocks and tossed 2 arrow into the get fixed pile.
    I re-called my local Mathews dealer and he noted to me that 4 Z7 Extremes have been in his shop with similar problems over the last 2 days.
    I wonder if I am at the point to change arrows and nocks? Here is some good news my broadheads are patterning very well, I use the same arrows obviously with my broadheads but these arrows only get shot on occasion not the hundreds of times I shot the others. Could the bemans be worn out? A friend brought his Reezen over to check to see if I was a bigger idiot that he was thinking I was and I shot his bow. I was able to get a pattern that you would normally expect circular all arrows within a fist sized circle at 20 and 30 yds. I have pictures of my patterns if that helps.
    What do I do now? Arrow nock suggestion? Could there be something bigger wrong with my bow?
    THANKS AGAIN FOR THE HELP
    Todd
    September 27, 2013 at 8:13 am #596534 Back to Top REPORT
    gjarcher
    gjarcher

    Age: 70
    Joined: 10/3/2006
    Location: Colorado
    View My Bows
    At this point, I would analyze the nock height versus the centershot. These two settings are like a “push-pull” adjustment, in that if the nock height is too high it can be compensated by a centershot that is out too far, and for a centershot in too far the nock height can compensate by being set lower. These conditions can produce bullet holes in paper, but not good groups (see Easton Arrow Tuning and Maintenance Guide, page 9 Good Arrow Flight-Poor Group)
    http://www.eastonarchery.com/img/downloads/software/tuning_guide.pdf

    What is the nock height? Using a bow square and with the QAD launcher full up measure the height the nock point is above perpendicular.
    QADnockheight

    What is the centershot? Using a ruler, measure the distance from the rest mount hole to the centerline of the arrow with the launcher full up.
    Z7Mag Centershot

    September 27, 2013 at 10:53 am #596554 Back to Top REPORT
    bow-drawn
    Bow Drawn

    Age: 62
    Joined: 11/14/2007
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    Vertical patterns or high /low shooting is what gjarcher is pointing out with rest or nock settings or center shot. Nock pinch will cause your pattern to be so random it makes no pattern to it.

    I was having my fixed blade 125 gr. broad heads hitting low to my 125 gr. field points by 2″ maybe 3 inches consistently at 20 yards. Plus my FP pattern was a bit off center. All I did was to adjust my arrow rest up about 1/32″ and afterwards I’m hitting solid with my field points.

    If you are hitting high try moving the rest down by 1/32″ to see if it moves the POI down with it.  Small adjustments can mean inches down range so make small adjustments then see what your pattern is  consistently at the target. Evaluate that before you make any more adjustments to your setup.

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