Since beginning the
work of experimenting with and building a few rifles for shooting sabotless
bullets, It must be said that I have become spoiled! Excellent accuracy
was achieved right from the start with minimal effort and at very high levels
of performance. I had never shot so many nice targets in such a short period
of time using a wide range of different bullet weights and types at the
highest load levels possible. Elimination of the plastic sabot eliminated
the associated problems and limitations of sabots and resulted in production
of a rifle that is more versatile and capable of significantly higher performance
levels than previously possible.
What are the
limitations or problems
associated with plastic sabots? They are as follows:
1.
Load pressure is limited.
In a rifle using saboted bullets, the sabot serves as the
link between the bullet and the rifles bore. Since the sabot is made from
plastic, it has only limited strength. If load pressure goes above certain
limits, the sabot will fail and loose its ability to function with resulting
poor accuracy.
2.
Accuracy at very high velocity is difficult to
achieve.
Accuracy at very high velocity levels is much more likely
to suffer because the limited strength of the sabot may not be able to withstand
torsional forces imposed by the barrels rifling.
3.
Barrel rifling twist rate which determines what
weight and speed bullets can be shot is limited.
If a rifle barrels rifling twist rate is too fast, it
becomes difficult if not impossible to shoot a saboted bullet at highest
velocity because the soft plastic sabot will not withstand the high shear
/ torsional forces imposed by the fast twist rifling. If shooting plastic
saboted bullets from a barrel with fast rifling twist then velocities must
be slower to achieve accuracy.
If high velocity is to be achieved
with good accuracy using saboted bullets then the barrel rifling twist must
be slower. The use of the slower twist rate limits the weight of bullets
that can be shot. If the longest and heaviest bullets are to be shot at high
velocity then, faster twist rifling must be used which eliminates the possibility
of using plastic sabots if expecting accurate results.
4.
Plastic sabots are affected greatly by temperature.
If best accuracy is to be obtained when
shooting saboted bullets, then careful attention must be paid to temperature.
As barrel temperatures rise the plastic sabot gets softer and loses strength
which degrades accuracy. That means that a significant waiting period between
shots is required to avoid overheating the rifles barrel if best accuracy
is desired. Also, hot weather makes things even worse even to the point
that a load may require considerable reduction if any accurate shooting is
to be done.
The
advantages gained through
the use of sabotless bullets are therefore as follows:
1. There is no limit to the "safe" load pressure that
can be used because an unsaboted solid copper or copper jacketed bullet can
easily withstand maximum safe working pressures without blow-out or other
failure.
2. Unsaboted solid copper or copper jacketed bullets
are strong enough to withstand any obtainable velocity and still give excellent
accuracy.
3. Any sufficiently fast rifling twist can be used when
shooting sabotless copper or copper jacketed bullets because the bullet
material strength is more than sufficient to withstand torsional forces.
4. Temperature is of much less concern when shooting
sabotless bullets and great accuracy is still obtainable without long waits
for barrel cool down. Hot weather is also of little concern.
What are some
disadvantages associated
with shooting sabotless bullets?
As with anything, there are always some negatives that
need to be dealt with. One disadvantage is as follows.
1. The bullet size as related to barrel bore size is
very critical. If the bullet is too loose a fit in the barrel bore, misfires
or poor ignition with inconsistent results and poor accuracy will result.
If the bullet is too tight then loading will be difficult if not impossible.
Many bullets may require resizing to obtain the proper fit. A bullet sizing
die or dies are provided with Swing-Lock sabotless rifles to assure the customer
can obtain bullets to the exact size needed. Also, future Swing-Lock rifles
will use precision barrels of the proper size which will allow the use of
some already commercially available bullets ( e.g. Parker Ballistic Extreme
) which will fit properly without the need for resizing. Bullet sizing dies
will still be provided to allow use of other bullets as well.
To be fair, it should be mentioned
that the above disadvantage regarding sabotless bullets brings to light
an advantage with regards to saboted bullets which is the fact that the
barrel bore to saboted bullet fit is not nearly so critical. The soft plastic
sabot allows for errors which cannot be tolerated when shooting sabotless
bullets.
RESULTS WITH THE NEW SWING-LOCK SABOTLESS
HIGH PERFORMANCE RIFLE
The
two targets as shown below are a good representation of just
how versatile the above rifle shown can be. The target on the left was shot
using the possibly impractical yet interesting Hornady 185 gr XTP bullet
at a velocity of over 3300 fps and group size of about .91 In. It is plenty
accurate enough for obliterating varmints at shorter ranges. While, the target
on the right was shot using the Barnes solid copper Super Shock 500 gr X
bullets at approximately 1870 fps with a group size of approx. .59 In. Considering
that bullet can be shot at over 2130 fps it could certainly do the number
on an elephant or buffalo over in Africa! A very neat thought indeed.Varmints
or elephants all with one rifle!
