Crossbows - Everything about Building, Modding, and Using your Crossbow Gear

Latest topics

» Wooden Crossbows - Seeking Info
by Franck Yesterday at 4:16 pm

» crossbow prod material/what type of steel
by Franck Yesterday at 4:11 pm

» Ball shooting Crossbows worth the bother
by septua Thu Jul 19, 2018 11:07 am

» my composite crossbow lath project
by stuckinthemud1 Wed Jul 18, 2018 1:35 pm

» Limb harding\ tempering ?
by ragumup Wed Jul 18, 2018 2:03 am

» how made homemade (reverse) crossbow ?
by Ricardo Sat Jul 14, 2018 3:56 pm

» Pump action crossbow (powerful)
by Ivanhoe Fri Jul 13, 2018 7:50 am

» nut from antler
by OrienM Thu Jul 05, 2018 8:50 am

» Nut from a pool que ball?
by drawknife Sun Jun 17, 2018 5:29 am

» Trouble with my Gafa
by drawknife Fri Jun 15, 2018 2:56 am

» Do all triggers Have claws - what types and claw or no claw
by globalmark Thu Jun 14, 2018 12:19 am

» For Sale: Masai Crossbow
by TonyU Mon Jun 11, 2018 1:15 pm

» Medieval composite bows
by juanjo Fri Jun 08, 2018 5:10 am

» yew and sinew prod help needed
by stuckinthemud1 Thu Jun 07, 2018 1:34 am

» Small gothic crossbow (with wooden lever)
by OrienM Fri Jun 01, 2018 10:35 am

» Binding on the stirrup
by Geezer Sat May 26, 2018 7:26 am

» horn inlay and veneer
by OrienM Thu May 24, 2018 8:44 pm

» Presentation
by c sitas Wed May 23, 2018 4:31 pm

» My latest crossbow
by drawknife Tue May 22, 2018 3:13 pm

» The Arbalist Guild - Around the World
by stuckinthemud1 Sun May 20, 2018 5:32 am

» angles and rivets
by Geezer Fri May 18, 2018 1:16 pm

» morticed nut blocks
by Dark Factor Wed May 16, 2018 12:02 pm

» Crossbow triggers
by Croftage Mon May 14, 2018 1:41 pm

» Cocking lever
by c sitas Fri May 11, 2018 8:09 am

» Late roman crossbow
by Dark Factor Wed May 09, 2018 10:27 am


    Why do match target bolts work so well?

    Share

    rolynd
    Techno Weeny

    Lets put a laser on it!!!


    Techno WeenyLets put a laser on it!!!

    Posts : 56
    Join date : 2011-05-16

    Why do match target bolts work so well?

    Post by rolynd on Wed Mar 20, 2013 5:14 am

    Hi guys,
    I am looking for Information on how and why these match target bolts work so well. When first looking at those I would have never thought that these could be so accurate.
    I am speaking of those unfletched totally front heavvy and short bolts like these:

    They are shot from these target crossbows:



    They are shot at distances of 30m and a "group" of 1cm (they actually cannot shoot groups, only a single arrow per target because of the accuracy!) is considered bad! Shocked Current World record is 298 points out of 300 possible.
    Does anyone have some specs on these bolts? Weight? COG? I always thought that a bolt would need fletching to stabilize it in flight and some rotation would add to the stability even more. These only have stabilisation from drag on the small nub at the end. And no spin ?


    Also the COG on regular crossbow bolts is just slightly forward of the center while these seem to be totally front heavvy?


    Has anyone of you experience with these kind of bolts? Are they only good for short distances?


    I think the accuracy is helped by the precision build of the Match target crossbows, AFAIK they use some kind of "sled" riding in the bolt groove to get a consistant release with no side deviation but nevertheless the bolts seem to do quite well aerodynamically.
    Regards
    Rolynd
    avatar
    Geezer
    Master Crossbowyer
    Master Crossbowyer

    Posts : 1032
    Join date : 2010-01-12
    Age : 70
    Location : Austin, Texas, USA

    Re: Why do match target bolts work so well?

    Post by Geezer on Wed Mar 20, 2013 7:30 am

    It's my suspicion that they Don't work very well. What's more, the slider used on these outdoor Swiss crossbows is bound to eat energy that could go into the bolt. What's important to understand is that the bolts are very consistently made, to close tolerances, and the bows are constructed to reduce variables to a minimum. Since you only shoot one bolt over and over (with the same side up, by the way) you get very consistent flight over a specific range. That means the target archers can concentrate on their form, knowing that all crossbows in the competition are essentially identical.
    In the world of sailing, there's a class of sloop called 'lightning', they arent the fastest boats of their size, far from it, but they are very close to identical. That means winning and losing is almost entirely due to operator-skill, not technology.
    Geezer

    rolynd
    Techno Weeny

    Lets put a laser on it!!!


    Techno WeenyLets put a laser on it!!!

    Posts : 56
    Join date : 2011-05-16

    Re: Why do match target bolts work so well?

    Post by rolynd on Wed Mar 20, 2013 9:00 am

    So its more like dealing with the same error or deviation on every shot and once the crossbow shooter has sighted in the bow he can just concentrate on form.
    I am aware that the slider uses up energy but at these distances I dont think they mind much, its not that they have to rely on penetration and energy ,as its not hunting but only precision counts.
    But still then, these bolts must fly relatively good to produce the same error every time. I would have thought such a short bolt is more prone to unpredictable or erratic flight patterns without any great means of stabilisation. But that does not seem be the case.
    avatar
    Gnome
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 409
    Join date : 2011-10-16
    Age : 54
    Location : North Georgia

    Re: Why do match target bolts work so well?

    Post by Gnome on Wed Mar 20, 2013 9:44 am

    My understanding is that medieval bolts were typically fletched with no attempt to add spin, just drag at the back to keep the pointy end forward. With the COG so far forward and the drag inducing nub at the back, those match points don't have much choice but to maintain the correct attitude in flight.

    Gnome

    rolynd
    Techno Weeny

    Lets put a laser on it!!!


    Techno WeenyLets put a laser on it!!!

    Posts : 56
    Join date : 2011-05-16

    Re: Why do match target bolts work so well?

    Post by rolynd on Wed Mar 20, 2013 10:13 am

    Well, must be then.
    I would love to see a slo-mo vid of one of these in flight!
    I begun to think of blowgun darts and these also fly well with only a drag inducing cone at the end and are accurate. Maybe I will make one of those short bolts and do a few tests for fun, at least you do not have to worry about the correct spine, guess these do not flex any:D
    avatar
    kenh
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 769
    Join date : 2012-08-03
    Age : 70
    Location : Living Aboard a Sailboat in Fort Myers, FL

    Re: Why do match target bolts work so well?

    Post by kenh on Wed Mar 20, 2013 10:15 am

    ... like a sinker glued to the end of a straw, guess which end is gonna go first!
    avatar
    kiwijim
    Tinkerer

    If there is a will, there is a way.


    TinkererIf there is a will, there  is a way.

    Posts : 62
    Join date : 2009-12-10

    Re: Why do match target bolts work so well?

    Post by kiwijim on Sat Mar 23, 2013 10:52 pm

    The slider may be useful for reducing efficiency and speed, although these are not reason for its use. Let me explain..... if those bolts were travelling too fast, they would be all over the place Their profile reminds me of a 'match' air rifle pellet- front heavy and a skirt to create drag and stability. With competition air rifle shooting, the competitors are prepared to sacrafice speed, and a good deal of $, to achieve consistant accuracey.

    Sponsored content

    Re: Why do match target bolts work so well?

    Post by Sponsored content


      Current date/time is Sat Jul 21, 2018 5:42 am