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HOW TO CHOOSE A BOW
Most of the bows today are fine pieces of equipment. Manufacturers have
improved the bows to a point where breakage is not a problem unless you are
trying to shoot super fast with light arrows. All of the bows, from the least
expensive to the most expensive will probably shoot more accurately than you.
You need to look for features that suit you and the way you are going to use
the bow. Here are some features to consider in your purchase.
Bow Length - The trend today is for very short bows. You have to shoot a
release aid with these bows and they won’t work for you if you have a long
draw. Longer bows tend to be more forgiving. Some may argue with that
statement, but look at the archers that shoot the indoor targets where they
don’t just shoot for bulls-eyes. They shoot for the x in the center of the
bulls-eye. The winners are shooting bows that are at least 48” long. Short bows
are handy in tight situations, like hunting from a blind.
Bow Weight - The trend is very light weight bows. A light bow is nice if you
are packing it all day on long hunts. Light bows tend to not be as accurate as
a heavier bow. Most target shooters use heavier bows and add stabilizers. More
mass is more stable. Check out target rifles. They all have heavy barrels. More
mass also absorbs vibrations better, although there are a number of products on
the market now that do a good job of absorbing vibrations.
Brace Height - This probably influences accuracy and speed more than any
other feature. Brace height is the distance from the string to the grip of the
bow. A lower brace height gives a longer power stroke so the arrow absorbs more
energy and is faster. A low brace height also keeps the arrow on the string
longer so any irregularity in your form has more of an effect on the arrow.
Bows with a brace height below 7” tend to be a little tricky to shoot for
hunting.
Cams - The larger aggressive cams give more speed. They also are harder to
draw. There is not much difference in drawing a 70 lb. smooth cam and a 60 lb
aggressive cam. Arrow speed will also be similar. You can’t get more out of a
bow that you put into it.
One or Two Cams - Throw out the advertising hype and they both do the same
thing. Timing on an aggressive 2 cam bow is critical. Timing isn’t near as
critical on a soft 2 cam bow. Timing is the roll over of the cams. They need to
roll over at the same time. The nocking point will travel up or down if one cam
rolls over before the other. The nocking point will move more with a radical
cam with big lobes. Timing is not much of a problem with the newer 1 cam bows
so they can have aggressive cams. There was nocking point movement on the early
1 cam bows. You also can have nocking point movement with a 1 cam bow because
the nocking point is not in the center of the string, like on a 2 cam. You have
twice as much string above the nocking point as below because the string goes
over the idler wheel and back down to the cam. String stretch will move the
nocking point. How much string stretch you get depends on the string material.
Newer bow string materials don’t stretch much after a few hundred shots.
Bow Draw Weight - Today’s 50 lb bows will kill just about any animal you
will hunt in North America. Don’t get a
heavier bow weight than you need. You should be able to draw the bow straight
back without raising the bow or having to put a lot of effort into it. You need
to be able to draw a bow in slow motion after you have been sitting on a stand
in cold weather for several hours.
Draw Length - Most people today have too long of draw length. They try to
pick up speed by increasing the draw length. That causes tension in the muscles
which reduces accuracy and causes target panic. You should be comfortable at
anchor when pulling into the wall. That is especially true with the short
valleys on bows today. Creep just a little while you are aiming and you are out
of the valley and holding the peak weight of the bow. That can cause you to
trigger the arrow and hopefully it doesn’t fly into the next county.
INFLUENCES ON SPEED
Speed is based on the stored energy of the bow and arrow weight. Some bow
features store more energy than others. Here is list of the items that control
speed and the approximate speed you can gain.
·Peak Weight - A change of 5 lbs. of peak weight
is equal to about 10 f.p.s.
·Draw Length - An inch change of draw length is
equal to about 10 f.p.s.
·Arrow Weight - A change of 25 grains of arrow
weight will equal about 5 f.p.s.
·Brace Height - An inch change in brace height is
equal to about 5 - 10 f.p.s.
These are rough estimates because many times if you change one you have to
change something else. For example, increase the draw weight or draw length and
you might have to shoot a stiffer arrow, which is heavier. You also get
diminishing return as you reach the extreme. Increasing the draw weight from 85
to 90 lbs will not have as much affect as increasing it from 45 - 50 lbs
because the percentage of change.
In addition to this, some bows use the stored energy more efficiently.
Needle bearings in the cams will reduce friction and increase speed. Limb
design can also make a difference in efficiency. Others like the type of cable
slide, string material, peep sight, etc., also make a difference.
ADVERTISED SPEEDS
Manufactures advertise AMO speed and IBO speed. AMO is the Archery
Manufactures and Merchants Organization. IBO is one of the largest 3-D shoot
organizations. AMO speed is with a 540 grain arrow shot from a 60 lb. bow with
a 30” draw. IBO uses a 70 lb. bow and a 350 grain arrow because that is the
lightest arrow and heaviest bow allowed in their shoots.
The speeds the
manufacture list are likely to be faster than you will shoot. Most bows come
with an adjustable draw length. 30” draw may be obtained with 3 different cams
that cover 3” of draw adjustment. Those 30” draw lengths will all have
different speeds. Some manufacture’s draw lengths run long so what they call
30” may actually be 30 3/4”. That will increase the speed rating by up to 5
f.p.s. In addition to all of that, many test their bows with no nocking point
on the string because that additional weight on the string will reduce speed by
a couple of feet per second. Use the manufacture’s rating as a rough guide.
They may vary by more than 8 f.p.s. from an independent test. 5 f.p.s. would
not be noticeable to anyone shooting a bow. It generally takes 10 - 20 f.p.s.
to make any noticeable difference. You can figure bows that are within 5 f.p.s.
speed rating are equal because of the differences in their testing.
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