The E3 Enhanced Bolt from Knight’s Armament features a
number of components designed to make this bolt the most durable and reliable bolt
available. It is a proprietary bolt specifically designed for our SR15 and 16
models. The E3 Bolt boasts several features that add to the its overall performance
such as the enlarged bolt face, rounded lugs, reduced cam pin, and proprietary
extractor and firing pin designs.
This E3 Bolt is manufactured with an enlarged bolt face that provides more
positive engagement in the chamber and lugs which are rounded to help to reduce
chipping, cracking and snapping. This strengthened design helps to increase the life
of the bolt and ensure a proper seating each time the weapon cycles.
The E3 Bolt’s extractor design is also a unique achievement that helps to
provide an extremely reliable component. It’s shaped like a rounded ‘T’ and
sometimes referred to as a ‘butterfly’ shape. The pivot point of the extractor is
shifted forward to help balance out the extractor and apply constant pressure on the
shell which reduces cases of extraction failures. Another strong feature of the
unique design of this extractor is the use of two full size extractor springs, as
opposed to the standard micro spring. This allows for a reduction of relative
compression while the extractor is in motion and provides a failsafe in case one
spring fails. The bolt will continue to function properly and afford a user the
opportunity to continue with their mission or firing schedule.
The E3 Bolt is designed with a thinner Cam Pin and Firing Pin whose overall size has
been reduced. The thinner Cam Pin allows for a thicker bolt web which is a common
failure point in normal bolts. The reduction of the Firing Pin size is to
accommodate the thinner Cam Pin.
The full capabilities of the E3 Bolt are realized when exposed to full auto
or extremely high cyclic firing rates yet the bolt performs gracefully under casual
firing conditions. This component was designed to be exposed to the most stressful
and unrelenting conditions and exceed expectations for durability and service life.
Knight’s Armament employs a hammer-forging process on a
number of our barrels and chambers, which serves to increase the quality of their
interior finish, as well as increasing the durability and life of the barrel. These
barrels are then Chrome-lined to further the lifespan of the barrel and increase its
resistance to fouling and corrosion.
The first step is to take a drilled barrel and hone the interior to a fine,
clean finish. The barrel is then placed onto a mandrel with the rifling pattern
ground in relief across it. This setup is then placed between opposing power hammers
which literally hammer the barrel onto the pattern found on the mandrel. The barrel
setup is rotated and the hammers continue to forge the barrel into its final shape.
Once they complete this process, the barrels are heat treated in order to relieve
the inherent stress created during this process.
The Chroming process is applied after the Hammer Forging. At this point the interior
of the barrel is basically lined with a layer of chrome and bonded to the forged
steel. Chrome is approximately twice as hard as standard 4150 steel and also resists
the lead and powder that bare steel will normally absorb into its pores. This allows
the barrel to be exposed to the higher temperatures and pressures of high firing
schedules while still maintaining accuracy, durability and reliability. The end
result is a denser, stronger barrel that will endure a higher round life than a
Standard Stainless Steel or Chrome Moly barrel.
Quick Detach Coupler
The Quick Detach Coupler (QDC) line of Sound Suppressors
and Muzzle Devices are proprietary items designed for secure interoperability. The
coupling device itself consists of multiple ball bearings arrayed in a circular
pattern which fit into sockets specifically machined into various muzzle devices to
accept the QDC. The bearings are aligned with the sockets by way of a V-shaped notch
that seats the device onto an index pin. Once aligned, a simple twist of the outer
retaining ring locks the device securely into place.
This system was developed to provide fast and easy operation and
interoperability between weapons and suppressors. Knight's QDC line of sound
suppressors all feature this method of attachment. Various muzzle devices, such as
the QDC Flash Suppressors and the MAMS muzzle break, also feature the QDC pockets to
accept sound suppressors equipped with this coupling device. Secure interoperability
and intelligent, efficient design are the intended goals of this quick and easy
Knight’s Armament designed this system to give shooters
the maximum amount of options in their controls. Under this design all of the
weapon’s major controls can be accessed from either side of the lower receiver.
Left-handed shooters see the immediate benefits of being able to access the weapon’s
controls in a more intuitive manner; however, there are a number of other benefits
that right-handed shooters will enjoy under this system.
Competition shooters benefit from these controls from the increase of speed
that is achieved through components such as the right-side bolt catch. Trainers
enjoy the variety of options because they can watch their trainee from either side
of the weapon and even manipulate the weapon’s controls from the non-operating side.
KAC has also introduced modifications to the design such as the scalloped safety
selector switch. This allows a lower profile for the selector switch on the
non-operating side of the receiver which helps to relieve any interference between
the switch and a shooter’s glove or hand. For the maximum amount of configuration
and operation options, Knight’s Ambidextrous Controls offer a sure solution.
Stage Match Trigger
All of the weapons available from Knight’s Armament come
equipped with a 4.5lb, 2-Stage Match Trigger. This type of trigger mechanism uses a
system where, during the rearward squeeze of a trigger, it cycles through two stages
The first stage is a ‘no-poundage’ stage where hardly any resistance is felt
during the rear-ward squeeze. There is a center point at which point resistance is
felt and the second stage of the trigger begins. At this point, 4.5 pounds of force
is required to squeeze the trigger through the second stage and cause the weapon to
Our 2-stage trigger is meant to inform a shooter of exactly where their weapon is
going to fire. This bolsters a firer’s confidence and can also assist in reducing
trigger jerk, thereby increasing accuracy. The 4.5lb 2-Stage Trigger from Knight’s
Armament is a highly calibrated and smooth component that is sure to be a welcome
addition to any setup.
M-LOK is a modular locking accessory mounting system
that is a direct attachment method for hard mounting accessories to a negative space
mounting point. The M-LOK attachment system allows the user to put mounting rails
only where they were needed, as opposed to covering the entire surface with mounting
rails, which are then covered with panels. The system also allows direct mounting of
accessories, such as fore-grips and flashlights, with no rail interface needed.