Heckler And Koch HK94 Instructions

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Fig. 31  Retracing the cocking lever     Fig. 32  Releaseing the coking lever 
						

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OPERATING PRINCIPLE
The weapon is loaded and cocked, with the safety off.
Pulling the trigger releases the hammer, which strikes the firing pin.
The cartridge is ignited. The powder gases thus generated drive the
bullet out of the barrel. At the same time, these gases also exert pressure
on the cartridge case.
This causes forces to act on the bolt head face; a portion of these forces
is transmitted to he receiver and a portion to the bolt head carrier, via
the locking piece; the balanced angular ratio of the locking piece and
barrel extension results in a delayed recoil movement of the bolt head.
This guarantees that the bolt keeps the barrel locked until the bullet has
left the muzzle 
						

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Fig. 33  Bolt in locked position 
						

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After the locking rollers have been fully cammed into the bold head, the
bolt can continue its recoil movement. In the course of this movement,
the empty cartridge case is ejected and the hammer recocked.
At the same time, the recoil spring is compressed, which returns the bolt
to its forward position. During the course of this process, a new round is
chambered from the magazine. The extractor engages the extracting
groove in the cartridge case. As a result of the bevelled surfaces of the
locking piece, the locking rollers are cammed against the supporting
surfaces in the barrel extension (Fig. 34). The weapon is now ready to fire
again. 
						

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Fig. 34  Bolt in unlocked position 
						

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STRIPPING THE RIFLE FOR CLEANING
Engage the safety!
Remove magazine.
Unload chamber; retract cocking lever and make sure that the chamber
is clear. Let the cocking lever snap forward.
Unhook carrying sling from front sight holder.
Remove butt stock locking pin and put it in the tubular rivets in the fixed
butt stock.
Slide off butt stock and back plate (Fig. 35). Remove grip assembly.
Retract bolt assembly by means of the cocking lever and remove it from
the receiver (Fig. 36).
Remove handguard. 
						

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Fig. 35  Removing the butt stock
Fig. 36  Removing the bolt assembly 
						

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Stripping the bolt assembly
Remove recoil spring from recoil spring tube by edging it off in the
rearmost position.
Rotate bolt head 90° toward your body and detach it from the locking
piece. Remove locking piece, firing pin and firing pin spring from the bolt
head carrier (Figs. 37 and 38).
To assemble the bolt assembly, insert firing pin, firing pin spring
and locking piece into the bolt head. Insert all parts in the bolt head
carrier in such a manner that the lug on the locking piece is guiding through
the recess in the bore of the bold head carrier.
Rotate bolt head until you hear it engage.
Press recoil spring into the recoil spring tube.
Stripping the pistol grip with trigger mechanism
Uncock hammer (spring).
rotate selective fire lever until it is in a verticle position, then pull out.
Remove trigger assembly housing.
Note: Further stripping of the trigger assembly housing may only be
performed by ordnance personnel. If the trigger assembly housing is
severly fouled, it can be washed out in a cleaning solvent. 
						

							39
   Fig. 37  Removing the
bolt assembly components
Fig. 38  Stripping
the bolt assembly 
						

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REASSEMBLING THE RIFLE
Attach handguard.
Insert the assmbled bolt with recoil spring into the receiver (locking rollers
must rest inside the bolt head).
Attach grip assembly (Fig. 39).
(Set safety lever on grip assembly on “O”.)
Slide fixed or retractable butt stock onto receiver and insert locking pin.
Hook carrying sling into the eye on the front sight holder.
Check the proper reassembly of the rifle by performing several cocking
motions.
Failure to function
On principle operate the cocking lever and continue firing. Should the
rifle fail to fire, put at safe, remove the magazine, unload the rifle and
ascertain the caus of malfunction.