The
HK33 is a 5.56mm
assault rifle developed in the 1960s
by West
German
armament manufacturer Heckler & Koch GmbH (H&K),
primarily for export.
Capitalizing on the success of the G3 design, the company developed a
family of small arms (all using the G3 operating principle and
basic design concept) consisting of four types of firearms: the
first type, chambered in 7.62x51mm
NATO, the second—using the Soviet
7.62x39mm M43 round, third—the intermediate
5.56x45mm caliber and the fourth
type—chambered for the 9x19mm
Parabellum pistol cartridge.
The HK33
series of rifles were adopted by the Brazilian Air Force (Força Aérea
Brasileira or FAB), the armed forces of Thailand
and Malaysia
where they
were produced under a license agreement. The rifle was also
license-built in France
by MAS and in
Turkey
by MKEK. The HK33 is
no longer manufactured or marketed by Heckler & Koch.
Design details
A Thai Army Military Police member
with the HK33.
Operating mechanism
The HK33 is a
selective fire delayed blowback-operated weapon. It employs
a roller-locked two-piece bolt consisting of a bolt head and bolt
carrier. After firing, two cylindrical rollers in the bolt head are
cammed inward by inclined surfaces of the barrel extension and
locking piece within the bolt carrier under rearward pressure on
the bolt head, delaying the bolt's movement relative to the bolt
carrier which is withdrawing at four times the velocity of the bolt
head. After the rollers compress into the bolt head, clearing the
locking recesses of the barrel extension, both parts continue
moving back together, opening the breech and actuating the
extraction and feeding cycles. The breech is opened under very high
pressure, to increase extraction reliability the chamber is
fluted.
Features
The bolt also contains a spring extractor, an anti-bounce device
(that prevents the bolt from bouncing after impacting the barrel
breech) and a buffer. The lever ejector was placed in the trigger
housing (actuated by the recoiling bolt).
The HK33 has a hammer-type firing mechanism. In the standard
version, the rifle comes equipped with an ambidextrous trigger
group with a selector lever that is simultaneously the weapon's
safety (it has three positions: "S" or "0"—weapon is safe,
"E"/"1"—semiautomatic fire, "F"/"25"—continuous fire). The "safe"
setting mechanically disables the trigger. The rifle is fed from
25-round
steel magazines weighing 250
g or 40-round
aluminum
magazines (weighing 157 g). 30-round arch magazines were also
introduced for use with the rifle.
The weapon is aimed using adjustable
iron
sights with a rotating rear drum (corrected mechanically for
windage and elevation) that contains an open square notch used for
firing at 100 m and three apertures for 200, 300 and 400 m. The
receiver top cover has a series of recesses permitting the
attachment of a clamping mount (standard with the HK33,
G3, G3SG/1 and
MP5) for use with a telescopic sight
(typically the Hensoldt 4x24 scope) or a night vision device.
The barrel is equipped with a slotted
flash suppressor that enables the use of
rifle grenades and supports a
bayonet.
During its production life the rifle received several minor
improvements (these modified weapons are sometimes referred to as
the
HK33E). The fixed stock was strengthened and
the synthetic forearm replaced with a handguard that allows a
lightweight bipod to be attached and stowed into two recessed
grooves at the base. The shoulder pad in rifles fitted with a
telescopic stock was changed to a concave type used thus far in the
Heckler & Koch MP5
series.
Initially the rifle was produced with a
305 mm (1:12 in) twist rate barrel, which was later upgraded
to the faster 178 mm (1:7 in) twist rate (used to stabilize
new, heavier NATO
standard
SS109/M855 ammunition).
Accessories
Included with the rifle are a detachable bipod, bayonet (from the
G3), sling, cleaning kit and a magazine loader. Additionally, the
HK33 can be used to mount a
40 mm under-barrel
HK79 grenade launcher or a
blank-firing adaptor.
Variants
The HK33 is available in several configurations: the
HK33A2 (fitted with a rigid synthetic stock), an
accurized variant known as the
HK33SG/1 (with a
telescopic optical sight and improved trigger analogous to the one
used in the
G3SG/1),
HK33A3 (with a telescoping metal stock), the
HK33KA3 carbine (barrel reduced in length to the
base of the front sight post also equipped with a folding metal
stock; the short barrel cannot be used to launch rifle grenades or
attach a bayonet) as well as the compact
HK53
carbine, which features a short, 211 mm barrel, a forearm
derived from the
Heckler &
Koch MP5 submachine gun and a telescoping stock or a receiver
endplate cover (later models also received an open-style flash
hider).
The
HK13
light machine gun was also built
based on the HK33. It is fed from either box or drum magazines (the
latter has a 100-round capacity), has a quick-change heavy barrel
for sustained fire, shrouded with a sheet metal heat guard
(replacing the synthetic forearm) and a 2-point bipod
adapter.
Heckler & Koch also make a semi-automatic only variant of the
HK33A2 for the civilian shooting market designated the
HK93.
The rifle is disassembled into the following components for
maintenance: the receiver, stock with return spring and trigger
pack with pistol grip. The trigger groups can be swapped out to
meet the user's specific mission requirements. HK offers several
different trigger assemblies: a three-shot burst fire control group
with selector lever/safety (selector settings: "0"—weapon is safe,
"1"—single fire, "2"—2-round burst or "3"—burst, 3-rounds; the
selector lever is ambidextrous); a "Navy" trigger unit (three
settings: safe, semi and full auto fire) and a four-position
trigger group (selector settings: weapon safe, single fire, 3-round
burst and automatic fire).
Users
See also
Notes
References
External links
-made Istec
ISL-201 40 mm undercarried grenade launcher.
and the Police Service of Northern
Ireland.
.
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