Heckler And Koch HK SL8-1 Operators Manual

							1
TOP HEADER
Operators Manual
In a world of compromise, some don’t.
®
HK SL8-1 Rifle 
Caliber .223
(5.56mm) 
						

							SL8-1Sporting Rifle
Operators Manual
CAUTION: Read the safety notes before handling the 
SL8-1 Rifle!
®
© Heckler & Koch, Inc., 10/99, 11/99 (revised May 2000)
All rights reserved
HK, Inc., 21480 Pacific Blvd.
Sterling, Virginia 20166-8903 
United States of America
Telephone (703) 450-1900
Specifications and models subject to change without notice. 
						

							Maintenance and Service  ..................................................................38
Troubleshooting Guide ........................................................................41
Parts & Exploded Diagram ..................................................................42
Specifications ......................................................................................44
Firearm Service Record ......................................................................45
45
TABLE OF CONTENTS
TABLE OF CONTENTS
Safety Notes on the Use of the SL8-1 rifle ..........................................6
General ................................................................................................8
Assembly Groups ................................................................................10
Description of Assembly Groups ........................................................11
Group 1  Receiver with barrel, buttstock and attaching parts ........11
Group 2  Bolt Assembly ..................................................................12
Group 3  Buttstock Assembly (with trigger & safety mechanism) ..14
Group 4  Handguard  ......................................................................16
Group 5  Magazine ..........................................................................16
Handling and Operation  ....................................................................17
Operation of Parts ..............................................................................22
Disassembly of the SL8-1 ..................................................................24
Assembly of the SL8-1 ........................................................................28
Disassembly  and Assembly of the magazine ....................................30
Adjustment of the Stock and Cheekpiece ..........................................31
Adjustment of the Sights ....................................................................33
Optical Sights  ....................................................................................35 
						

							67SAFETY NOTES
SAFETY NOTES
• Always point the rifle in a safe direction.
• Before handling and before cleaning it has to be checked to
ensure that:
- The bolt is locked to the rear
- The rifle is unloaded (cartridge chamber empty)
- The barrel is free of obstructions 
- The magazine is empty.
• Keep your finger off the trigger when loading, unloading or
otherwise handling the rifle. Always place the trigger finger
outside of the trigger guard.
• Place your finger on the trigger only when your sights are
aimed at the target.
• Never use force when handling, disassembling, cleaning and
assembling the rifle.
• Disassemble the rifle only as far as described in this manual.
• Always wear eye and hearing protection when using the rifle.
• Take into account the fact that bystanders are also endangered.
Ensure bystanders are also wearing ear and eye protection.
• Only use factory-loaded and undamaged cartridges of the
correct caliber.
• Always mind that the muzzle area is free of obstacles during
firing.
• Store the firearm and ammunition in separate places.
• Discharging firearms in poorly ventilated areas, cleaning
firearms, or handling ammunition may result in exposure to
lead, a substance known to be associated with birth defects,
reproductive harm, and other serious injury. Have adequate
ventilation at all times. Wash hands thoroughly after exposure.
• Heckler & Koch does not assume any liability for events due to
disregarding this manual, improper handling, negligence,
improper treatment, use of improper or reloaded ammunition,
unauthorized exchange of parts or manipulations of the rifle.
• Remember, firearms safety begins with you. Read this operators
manual and be familiar with the safe handling of this firearm
before using it. Store all firearms in a safe and secure location.
Keep firearms away from children. Always be a safe shooter.
Keep this manual with the rifle. Safety Notes on the Use of the HK SL8-1
Clear the rifle! Before handling the firearm, “clear it!” Do so by:
1 •Make sure fingers are outside of the trigger guard and the
firearm is pointed in a safe direction at all times!
2 •ON SAFE – Rotate the safety/selector lever to the “Safe”
position (the white “S”adjacent to the safety/selector lever)
3 •REMOVE MAGAZINE – Depress the magazine paddle release
lever and remove the magazine from the magazine well.
4 •COCKING LEVER – Rotate the ejection port towards the
ground and fold out and pull the cocking lever rearward one or
more times to insure the chamber is empty. Watch for a live
round or empty case to be ejected. Move the cocking lever
upward slightly and lock it into the indent in the cocking lever
housing to lock the bolt open.
5 •BOLT CATCH – While holding the cocking lever fully rearward
use the trigger finger to press upwards on the bolt catch button
located in the front top corner of the trigger guard to lock the
bolt rearward.
6 •INSPECT CHAMBER – Inspect chamber for the presence of a
live round or empty case.
Visually – View chamber through open ejection port.
Physically –  Insert index finger through magazine well or
ejection port and feel for the presence of a round or cartridge
case in the chamber.
7 •Remove any live rounds or empty cases from the chamber or
from within the firearm or magazine before handling the firearm
further.
The HK SL8-1 is now considered “Clear.
WARNINGS
• Carefully read this operators manual before handling the rifle.
• Only use the rifle after you have fully reviewed and 
understand these instructions.
• Observe all notes on handling and operation. Failure to do so
may result in injury or death of the operator or bystanders.
• Do not use the rifle if you have previously ingested alcohol or
drugs.
• When passing the rifle between persons, the firearm must be
clear and the bolt should be open.
• Always treat the rifle as if it were loaded and ready to fire.
• Never point the rifle at anyone during handling. 
						

							89GENERAL
GENERAL
Figure 2 SL8-1 with mechanical sights (right side view)
Figure 3 SL8-1 Accessories
The HK SL8-1 semiautomatic rifle is a caliber .223 Remington civilian
sporting arm based on the G36 rifle currently used by the German Army.
The SL8-1 rifle is gas operated with a rotating bolt head. Its receiver,
pistol grip, buttstock, and handguard are all made of a high-strength
polymer material, resulting in a tough and lightweight rifle.
A mechanical sight is mounted on the Picatinny long rail found on the
top of the upper receiver. This sighting system can be easily replaced by
other sighting systems, including optical scopes.
A movable buttplate and cheekpiece are other features that can be
adjusted to the individual needs of the user.
The heavy barrel and the chamber are cold hammer forged and hard
chrome plated for durability and accuracy. The barrel is fastened and
centered to the receiver by means of a hex nut.
A cocking lever on the front end of the bolt head carrier can be swiveled
to the left and to the right for actuation by both left and right handed
users.
The magazine holds 10 rounds.
A bolt catch locks the bolt rearward (open) when the last round is fired
or an empty magazine is inserted and the bolt is retracted.
Figure 1 SL8-1 with mechanical sights (left side view)    
						

							11 Group 1  Receiver with barrel, buttstock and attaching parts
The receiver is made of high-strength fiber-reinforced plastic. It houses
all the other assembly groups. Inside the receiver there are guideways
for the bolt as well as contact surfaces for the pistol grip, the buttstock
and the magazine well. The barrel is fastened and centered to the
receiver by means of a nut.
CAUTION: The barrel nut should not be removed by the operator.Only HK certified armorers should attempt to remove the barrel.
On the right side of the receiver is an ejection port with an integral
cartridge case deflector. The cartridge case deflector directs the ejected
cases (at an angle of approximately 45°to the muzzle) away from the
shooter.
Handguard and magazine well are fitted to the bottom of the receiver by
means of removable locking pins.
The buttstock with trigger mechanism is fastened to the receiver by
means of two hex head screws. To fasten and unfasten them use the
HK special tool provided with the rifle.
Figure 5  
Receiver with barrel, gas system, mounting rail with mechanical sights
1. Barrel
2. Front sight
3. Mounting rail
4. Rear sight
5. Receiver
6. Magazine catch
7. Magazine well
DESCRIPTION OF ASSEMBLY GROUPS
10ASSEMBLY GROUPS
Figure 4  SL8-1 Assembly groups
1 Receiver with barrel, gas system, magazine well,
mounting rail with mechanical sights
2 Bolt assembly with recoil spring assembly
3 Buttstock assembly complete
4 Magazine
5 Handguard   
						

							13 The firing pin is retained by the firing pin retaining pin.
A cocking lever on the front end of the bolt head carrier can be swiveled to
the left and to the right for actuation by both left and right handed users. It
can also be locked in a 90°position to the left and right for use as a
forward assist.
Figure 7 Bolt assembly with recoil spring assembly
The recoil spring guide rod with the recoil spring is a separate unit and
fits into the bolt head carrier. Rearward movement of the bolt assembly
is stopped by a buffer in the buttstock.
Figure 8 Bolt assembly
1. Cocking lever 4. Retaining pin
2. Bolt head carrier 5. Cam pin
3. Firing pin 6. Bolt head
Figure 9   Bolt head
DESCRIPTION OF ASSEMBLY GROUPS
12DESCRIPTION OF ASSEMBLY GROUPSGas block
The gas block is fastened with a cross pin to the barrel; do no attempt to
remove it. After the bullet has passed the gas vent hole in the barrel, a
portion of the propellant gases are guided into the gas cylinder within
the gas block and actuate the gas piston.
The gas piston drives the bolt assembly rearward via the push rod. The
return spring on the push rod returns the rod to its starting position.
Figure 6 Gas system
Magazine well
The front of the magazine well engages into two support studs on the
receiver. For fastening the magazine well is swiveled upward. A locking
pin fastens both the pistol grip and the magazine well to the receiver.
When the locking pin is removed the magazine well is retained by the
magazine catch.
Group 2    Bolt assembly
The bolt assembly with the rotary bolt head is guided into the receiver
by metal guide rails molded into the polymer receiver. The bolt assembly
is driven rearward by the gas piston and forward by the recoil
spring.The bolt assembly serves multiple functions including; feeding the
cartridges, locking of the chamber, cartridge ignition, case extraction
and ejection, as well as for cocking of the hammer.
The bolt head is retained in the bolt head carrier by the cam pin which
also controls its rotary movement. Locking lugs are machined onto the
front of the bolt head. The spring-loaded extractor is located in a gap
between the locking lugs. Adjacent to the extractor is a spring-loaded
ejector.
1. Extractor
2. Ejector
3. Locking lugs (6 total)     
						

							15 Trigger and Safety Mechanism
The trigger and safety are integrated into the buttstock assembly.
At the front of the trigger guard there is a bolt catch button which is
used to hold the bolt open on an empty magazine or when fired “dry.”
There are safety selector levers on both sides of the grip. The
safety/selector levers can be placed in two positions:
“S”= Safe (white index line on the safety/selector     
lever pointing to the white “S”)
“F”= Fire (semi-automatic white index line on the
safety/selector lever pointing to the red “F”)
Figure 13  Trigger and safety mechanism
1. Bolt catch button
2. Hammer
3. Safety/selector lever
4. Trigger
5. Bolt catch 
Figure 14A Safety/selector position   Figure 14B Safety/selector position
“safe” “fire” (semi-automatic)
DESCRIPTION OF ASSEMBLY GROUPS
14DESCRIPTION OF ASSEMBLY GROUPSButtstock Assembly, complete
The buttstock is fixed to the receiver by the means of two hex head
screws which can be opened and closed with the HK Tool. The buttstock
includes an integral rear sling attachment point.
Butt plate and cheekpiece can be adjusted to the individual requirement
of the user by the means of spacers.
The trigger and safety/selector lever is located at the front end of the
buttstock.
Figure 10  Buttstock assembly complete
Figure 11   Figure 12  
Cheekpiece Buttplate with 
interchangeable spacers       
						

							17 Ammunition and Accuracy
By using ammunition with match bullets (like Sierra 62 grain Match King
#1410) or other match grade ammunition the HK SL8-1 will achieve the
best level of accuracy.
If used, handloaded ammo should not exceed the maximum gas
pressure specified by C.I.P. and SAAMI for the cal. 223 Remington
cartridge (5.56 x 45mm NATO). Follow the instructions of propellant and
bullet manufacturer.
Mounting Rail
The rail with mechanical iron sights is not designed to be a carrying
handle.
CAUTION: Except for loading and unloading the rifle there should beno finger placed between the rail and the receiver.NOTE: If the bolt is locked to the rear by the bolt catch and the
magazine is removed, a hard knock on the buttstock, like slamming
the gun to the ground will release the bolt. However, to avoid
damage to the rifle, the bolt should be pulled fully rearward andreleased.
Safe handling
Compared to the military issue G36 assault rifle, the trigger pull of the
SL8-1 is significantly reduced. If the weapon is loaded, avoid rough
handling and drops.
Because of the absence of a firing pin spring, a slight mark on the
primer can be seen after chambering a round. This has no influence on
the handling safety of the rifle; without pulling the trigger the gun will not
fire. Please avoid chambering the same round several times in
sequence as the bullet can be worked loose from the cartridge.NOTE: Use only .223 Remington or 5.56 x 45mm NATO ammunition
in the SL8-1 rifle. Damage caused by the use of improperly
assembled or remanufactured ammunition in the SL8-1 may void the
HK Warranty. Do not use ammunition assembled with corrosivecomponents (primers, propellants, etc.).
HANDLING AND OPERATION
16DESCRIPTION OF ASSEMBLY GROUPSHandguard
The detachable handguard encloses the barrel and the gas system. The
handguard is positioned at the receiver by means of two support studs
and is fastened there by means of a removable locking pin. The
handguard incorporates a sling attachment point and two threaded hard
points for accessory attachment.
Figure 15  Handguard
Magazine
The detachable box-type magazine holds maximum 10 rounds. The
magazine housing consists of impact-resistant transparent plastic which
allows the user to visually check the contents of the magazine from the
outside.
Figure 16 Magazine         Figure 17 Magazine disassembled
The magazine consists of:
1. Magazine housing
2. Magazine floor plate
3. Follower
4. Follower spring    
						

							19 Loading the Rifle
Method 1: No magazine in the weapon
The bolt is in its forward (locked) position
1 •  Set the safety/selector lever on “Safe.”
2 •  Swivel the cocking lever to the left or to the right, pull it all the
way to the rear (Figure 20) and hold it.
Figure 20  Operating the cocking lever
3 •  Push the bolt catch button upward to lock the bolt open
(rearward, see Figure 21)
Figure 21  Activate bolt catch, push upwards
4 •  Insert a loaded magazine into the magazine well until the
magazine catch clearly engages. Swivel the cocking lever out,
pull it all the way to the rear and release it.
The weapon is now loaded and set on “Safe.”
HANDLING AND OPERATION
18HANDLING AND OPERATIONCartridges assembled with projectile weights from 50-70 grains are
recommended for use with the SL8-1 rifle.
Loading of the magazine
1 •  Hold the magazine with one hand. Place a cartridge with the
other hand slightly forward of the the magazine lips and push
back and downward until the cartridge is held underneath the
lips.
2 •  Repeat this operation until the magazine is fully loaded and the
desired 10 rounds are inside the magazine.
Figure 18  Loading of the magazine
Unloading the magazine
Hold the magazine with one hand. Push the cartridges forward out of
the magazine with the thumb of the other hand. Do not allow the
cartridges to drop on a hard surface or they may become damaged.