Here is a topic which has been very interesting and enlightening to work
on. When it comes to muzzle brakes as used on muzzleloading rifles shooting
saboted bullets, it seemed that little information with any message of encouragement
was available. Saboted bullets just did not shoot well through previously
available muzzle brakes that we were aware of.
In our own way of thinking, it was believed that an adequately designed muzzle
brake should be possible and that with a very high performance rifle where
recoil is of concern, it might be a highly desirable option for some shooters.
Well, below you will see some pictures and computer models of a few muzzle
brakes which have shown very good results at maximum performance levels.
Some target photos are also included.
The muzzle brake shown below and on the Tactical style rifle as well
as the other "side-load" design brake have been tested using 250gr Hornady
SST bullets at well over 3100fps with exceptional results. Recoil reduction
was measured at 47% for the "hole ported" design and at a notable 17% for
the "side load" design. While recoil reduction is not nearly as good with
the "side load" design, it does provide for easy loading by inserting load
components through the side. The ported design can be loaded using a special
short starter tool or the brake can easily be screwed off by hand for direct
loading into the muzzle.
Testing was performed through the use of a rifle holding fixture that
is allowed to slide freely on a smooth surface during the firing sequence.
The test rifle was fired using a very light weight hydraulic triggering device
which did not detract from test results. To determine the amount of recoil
reduction, the rifle was simply fired with and without the muzzle brake using
the same load each time. With each shot, the distance traveled was measured.
After sufficient data was obtained the amount of recoil reduction was easily
calculated.
With study of the computer model below for the "hole ported" design muzzle
brake, the actual function of the brake can be explained. This design is
made with a large internal volume for efficient gas expansion which improves
the brakes ability to redirect high pressure exhaust out through the port
holes which are milled on a 45 degree reverse angle. Exhaust thrust pulls
the rifle forward thus reducing recoil. Angling the ports increases the amount
of recoil reduction. To allow the sabot to open for proper bullet release,
a smooth, unported section of internal surface is provided which eliminates
the possibility of sabot petals getting snagged on the port holes before
proper bullet release has been achieved. In this design, as the bullet begins
to exit the muzzle, the sabot will begin to open towards the inner smooth
wall of the brake housing. In normal fashion, the bullet is released from
the sabot and travels unhindered through the center tube and towards the
target. As the sabot moves forward toward impact with the beveled edge of
the tube insert, its petals travel over the outside of the tube insert. When
the sabot base impacts the beveled edge of the tube insert, the petals are
either sheared off of the base or ironed backwards as the sabot base is blown
through the tube insert. Petals which are sheared off are blown though the
port holes. It is theorized that the sabot base actually serves to provide
a momentary seal which helps in the recoil reduction process by making redirection
of exhaust gases more efficient. Increased muzzle blast may be an issue for
some shooters and bystanders with this brake.
With attention to the computer model below for the "side load" design muzzle
brake, in this design, the sabot with bullet inserted is slid through a side
port and started into the muzzle oriented such that the sabot petals are
in alignment with the muzzle brake ports. The ramrod is then used to finish
the loading process. In this design if the sabot is in proper alignment with
the muzzle brake ports, as the saboted bullet leaves themuzzle, the
sabot petals will open freely into the open port spaces giving a clean bullet
release. You will notice that the ports are quite long to allow sufficient
time for the sabot to open properly. In like manner as the other design,
the sabot base will impact the beveled edge of the tube insert at which time
the sabot petals will be sheared off or ironed backwards as the sabot base
is blown through the tube insert. This design does not give a high degree
of recoil reduction because gases are only directed somewhat side wards without
producing a rearward thrust component to pull the rifle forward. Some advantages
for this design would be ease of loading and less increase in muzzle blast.
Of greatest interest when testing these muzzle brakes was the high degree
of accuracy that was suddenly realized with extremely high velocity loads
which had previously not proven to be highly accurate. It is strongly felt
that the explanation for this can be found in how the muzzle brake affects
barrel harmonics. The muzzle brakes apparently provide a stabilizing component
which may greatly improve accuracy with the highest velocity loads. Two rifles
have been tested using these muzzle brakes and both gave much improved accuracy
when using the highest velocity loads. In all fairness it should also be
stated that when using loads of lesser velocity, accuracy did not improve,
but instead was decreased. Even so, a major purpose of the muzzle brake is
to decrease recoil especially as related to shooting very high velocity loads.
With that consideration, these devices work very well and for some shooters
may open the door to using much higher performance loads for even more accuracy
potential at even longer ranges.
Another observation is with regards to today's modern sabots. Some might
suggest that sabots will not function properly at the speeds reported on
this web site. Well, testing of these muzzle brakes certainly contradicts
that reasoning. If the sabots could not take the speed then accuracy as we
are reporting would not be possible with or without a muzzle brake.
More info is included below.
Here is the "hole ported" muzzlebrake. You will notice a notched
plate behind the tube insert. The notches provide a visual reference for
positioning the sabot petals in relationship with the rifling during loading.
Tactical style rifle with muzzle brake. The muzzle brake may be used on
other style rifles as well.
Here is an early style of side load muzzle brake which also gave great
accuracy at over 3000fps. This one has straight ports instead of helical
ports as shown in the computer model below.
Below is a computer model of the "hole ported" muzzle brake. A "slotted
port" can also be produced.
This is a computer model of a "side load" muzzle brake with helical ports
that match the rifling twist.
Below are some targets showing (3) shot clusters as shot through
muzzle brakes using 250gr Hornady SST bullets at speeds indicated.
Velocity for the left target is as indicated . Average velocity for the
right target was 3150 fps.
Average velocity for the left target was 3214 fps. Average velocity for
the right target was 3150 fps.
Muzzle brakes are made from heat treated 416 stainless
or chrome moly steel.
APPROXIMATE PRICE FOR MUZZLE BRAKE ON SWING-LOCK RIFLES ONLY: $200.00
