Re: Tapered bolts
- View SourceHi all,
I shoot with one set of tapered shafts, 11/32 with a very gentle taper on
the sides only so that they fit into the nut on my light crossbow. I don't
taper the top or bottom, since that encourages the string to skip
under/over the butt of the bolt, promoting a misfire.
The change to the aerodynamics is very slight, the feather fletches
probably change the flight properties much more than the slight taper I've
put on. And the weight difference is slight (at least according to my
mettler balance at work).
If the problem described is adjusting weight on the tip-end, then why not
just hollow out about 0.5cm of the wood shaft with a dremel and superglue
some lead solder onto it? The solder I own is 0.1 grams per 0.5cm IIRC.
I've gotten matched sets of bolts that are within 0.1 grams of each other
by this method.
I'm not sure if making a bolt more tip heavy will change your point of aim
(I don't use point of aim with a crossbow, all instinctive). But the more
tip heavy bolts will encourage them to see-saw off of the stock while
loading. Do you use your thumb to secure the bolt of some sort of bolt
clip? Either method should work fine.
If the bolt is too tip heavy (trial and error here!) I've found that it
will wobble up-and-down in flight, since the nose really wants to go into a
dive at the instant it comes off the stock (before wind resistance
stabilizes it -- fletch size does make a difference here).
Depending on the speed of your bolts, if there is a wobble there will be a
"myopic" (nearsighted) zone where the bolts will not group as well. As in,
when they hit the target, they are still wobbling in flight and the wind
resistance hasn't forced them to fly straight. If you're lucky, this zone
will be less than 20 yards.
Regardless, best of luck and shoot well!
-Lyev Davidovitch, AEthelmearc
- View SourceThe main problem is my nut is set up for 5/16" shafts only, so I would
have to have the full taper, and since I shoot 3 fletch, I can't really
leave the top and bottom thicker. The weight issue isn't really for the
tip end, but for the whole shaft. Right now my shafts are 325gr, and that
includes a 125gr. tip. This might be good for a 30yd. dead on aim, but
most of the shooting I do is 20yds or under. I have a spring steel bolt
clip. My bolts fly at 180ish fps, or they did last time I checked its
been a while, and a prod I think, ago. As they are now, my bolts don't
have any wobble anywhere, with the exception of a few that wobble for
about 5yds then straighten out.
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
- View SourceI must beg to differ on this point!! If there is any wobble of the bolt off
the bow it is a matter of tuning the bow and bolt. When I build a crossbow
I normally shoot a fletchless bolt and play with the prod setting(left and
right) and the bolt setting at both ends ie: The height of the center of
the shaft compared to center of the string. until the flechless bolt hits
consistently strait into the target at 20 yards(like paper tuning a
longbow). The rumor is that people who shoot unlimited crossbows
internationaly use a quarter at 50 meeter to test flechless bolts.
> If the bolt is too tip heavy (trial and error here!) I've found that ita
> will wobble up-and-down in flight, since the nose really wants to go into
> dive at the instant it comes off the stock (before wind resistance
> stabilizes it -- fletch size does make a difference here).
> Depending on the speed of your bolts, if there is a wobble there will be a
> "myopic" (nearsighted) zone where the bolts will not group as well. As in,
> when they hit the target, they are still wobbling in flight and the wind
> resistance hasn't forced them to fly straight. If you're lucky, this zone
> will be less than 20 yards.
> Regardless, best of luck and shoot well!
> -Lyev Davidovitch, AEthelmearc