Martin Archery Martin Compound Bow - Manual (Page 13)

A high nock set will cause porpoising.
Low nocking point. High nocking point
13
After completing the basic setup procedures, you are ready to fine tune your setup for the
best accuracy possible. There are four tuning methods described in this section. Some of
these methods may not apply to certain styles of shooting. Read the introduction to each
method carefully to make sure it applies to your shooting style.
•Bare Shaft Planing Test
The Bare Shaft Planing method of tuning works best when using a finger release. To begin
the Bare Shaft Planing test you will need three fletched arrows and one or two bare shafts.
You will also need a target that will catch the arrows without allowing the arrow to kick as it
stops in the target. This test will help you establish the correct nock and rest position, and
it will tell you if your arrow is the correct spine. Porpoising and Fish Tailing describe the
different flight disturbances you may encounter while tuning.
•Porpoising
Porpoising is identified by an up and down kick during arrow flight and relates to the
nock point adjustment. It is important to correct porpoising first because small left and right
disturbances could be nock point related. Start at about ten to fifteen yards and shoot three
fletched arrows into your target. Using the same aiming point, follow them up with a bare
shaft. After you get the bare shafts to impact with the fletched shafts, you may want to try
shooting them at a longer distance for a finer indication of arrow flight.
If the bare shafts impact below the fletched arrows, your nock point is too high. Move
your nocking point down in small increments until the bare shaft strikes with the fletched
shafts. If the bare shafts impact above your fletched arrows, your nock point is too low. Raise
your nock point in small increments until your fletched arrows and your bare shaft impact
together.
Repeat the above steps from a longer distance to make sure you have
completely corrected the nock point. Shooting from a longer distance will make minor
disturbances more apparent.
Fine Tuning Your Compound Bow