GTW I N - D E P T H W I T H C A L W A R D
S U P P R E S S O R S : P A R T O N E
H O W M U C H D O W E R E A L L Y K N O W A B O U T T H E M ?
Northern Irish rifl e and pistol expert Cal Ward delves into the subject
of suppressors in the first in a new series of technical articles.
Most people own one or more suppressors and assume they
know everything but that isn’t necessarily the case. In fact, I
feel few people know much about the topic although many
hold strong if unscientifi c opinions. Th e reason is simple.
Th ose who write about suppression – and more especially those who
show off their toys on YouTube – know little of
the science of sound while those who have done
serious research, often backed by large budgets
from mikitary industries, are keeping their trade
secrets to themselves. Th ese people can also call
on fully equipped workshops with the latest
gear to turn their ideas into prototypes which
are tested using sophisticated sound equipment.
People like myself who have an interest in this
topic all agree on one point – there is a LOT we
don’t know and even more we are not being told.
Suppressors are referred to colloquially as
“cans” and “silencers”. Th e terms “moderator”
and “suppressor” are more precise and mean
the same thing – a device fi tted to a fi rearm to
reduce its sound signature. Th e decibel scale
used to measure sound is logarithmic. Gun
shots are not composed of a single frequency
but produce a wide band of frequencies in a characteristic mix that the
human brain soon learns to associate with the discharge of a fi rearm.
A suppressor can deceive the brain and one that is especially good at
eliminating higher frequencies will seem quieter than one that eliminated
lower frequencies. Th e threshold of human hearing is zero decibels. A
quiet conversation is 56db, a BB gun is 101 db, a standard velocity 22 rifl e
is 13 db. Hearing damage begins at 140db. Th e pain threshold is 141db.
The ASE range of suppressors
is favoured by rifle maker
Fabian Connolly for their
durability and compactness.
A Heckler & Koch MP5 is 157db, a .45 pistol is 162db, an M16 is
165db, a howitzer is 183db and death to an observer occurs at 220db. Th e
Decibel scale is logarithmic like the Richter scale and each increment
represents a huge increase.
Th e fi rst commercial suppressor was patented in 1909 by Hiram
Maxim and resembled many of the baffl e-stack
silencers available today for .22 rifl es.
Th ere is a wealth of video material online
but one wonders how much suppression on
display is ballistic and how much is electronic.
Real sound waves arewmodifi ed every time they
are processed by microphones, speakers, fi lters,
Bluetooth, Wi-Fi, mp3 compression and so
on. Th e guy with the nearly silent Sten gun on
YouTube may not be as unobtrusive as he sounds
and the Hollywood myth of the 9mm pistol
that goes “phut” is just that – a myth. My .22
Anschutz heavy-barrel locked breech varmint
rifl e with its A-Tec suppressor goes “phut” and,
as far as I can determine, ballistic suppression
just gets louder above .22. Explaining this selfevident
fact is more diffi cult than you’d think.
When you own a suppressed .45 rifl e you
WHAT DO WE KNOW?
• Subsonic projectiles are quieter than
supersonics, which create a supersonic crack
• Subsonic (.22) suppressors are more eff icient
than supersonic suppressors
• Some designs are more eff ective than others
PEOPLE WHO HAVE READ A LITTLE MORE
WILL KNOW THAT:
• Suppressors trap, cool, slow down and then
release propellant gases.
• .22 calibre firearms can be suppressed to the
point where they can be called “silent”
• Automatic and semi-automatic firearms are
more diff icult to suppress
quickly learn is that a .22 is silent and everything else is just suppressed.
A subsonic 22 bullet is about 40 grains in weight with about two grains
of powder behind it and the small explosion of gas produced can be
suppressed by just about any container fi tted on the end of the barrel.
Th e most silent .22 is a locked breech rifl e with a long, heavy barrel and a
good quality suppressor. Th e least silent is a semi-automatic with a short,
light barrel, (lots of muzzle blast) and a cheap suppressor.