Heckler And Koch HK UMP45, UMP40 Operators Manual

							11
DESCRIPTION OF ASSEMBLY GROUPS
Assembly Group 1 
Upper receiver with barrel, folding buttstock attachment
components
The upper receiver is produced using fiber-reinforced plastics and
houses other subassemblies. The inside of the upper receiver contains
metal guideways for the bolt group as well as attachment points for the
lower receiver with magazine well and backplate. 
The barrel is inserted into and pinned to the upper receiver. The cocking
lever of the weapon is located above the barrel. It also serves to
manually lock the bolt in its open position. The right side of the upper
receiver contains the ejection port. The ejection port includes an integral
catch for engage-ment of the buttstock in its folded position.
The bottom part of the upper receiver includes the support bolts for the
lower receiver. The left side of the upper receiver includes eyebolts for
attachment of the carrying sling. 
The sights are fastened to the top of the upper receiver. They consist of
a flip-up type rear sight with diopter (peep) and u-notch apertures as
well as of the front sight post with front sight hood. The rear of the upper
receiver includes the hinge for the folding buttstock. 
Fig. 6  Upper Receiver with barrel, folding buttstock and attachment
components 
1 Upper receiver 5 Flip-up rear sight 
2 Barrel 6 Buttstock 
3 Front sight 7 Buttstock release button
4 Cocking lever  8 Carrying sling attachment 
points 
						

							12
UMP SUBMACHINE GUN
Buttstock 
The buttstock folds to the right along the upper receiver, and with the
stock folded, the UMP is only 17.72 inches (450 mm) long. The open
frame-type design of the buttstock also enables the weapon to be fired
with the buttstock folded. 
Pressing the catch releases the buttstock for folding. When folded, the
buttstock engages on the catch located on the forward part of the
ejection port. For unfolding, the buttstock is lifted off the catch. 
The buttplate has a rubber pad to ensure non-slip contact with the
shoulder. This cheek piece is also rubber covered to enhance shooter
comfort during firing. In the forward part of the buttstock a hole is
provided for insertion of the locking pin during disassembly. 
Fig. 7  Folding the buttstock           Fig. 8  Unfolding the buttstock
Assembly Group 2  Bolt Group 
The bolt group, together with the recoil spring assembly, is contained
inside the upper receiver. The reciprocal movement of the bolt group
provides for feeding and ignition of the cartridge, for extraction and
ejection of the spent case as well as for cocking of the hammer. The
right side of the bolt has a thumb recess for manual closing of the bolt
(forward assist). 
The recoil spring assembly pushes the bolt forward into the firing
position The cone-shaped support for the recoil spring assembly is
housed in the backplate of the lower receiver. The longitudinally
movable guide ring supports itself within the bolt.  
						

							13
DESCRIPTION OF ASSEMBLY GROUPS
The bolt group (Fig. 8 and 9) consists of:
1 bolt 
2 firing pin spring 
3 firing pin 
4 extractor 
5 firing pin retaining pin 
6 recoil spring assembly, complete
6a guide ring
6b support
Fig. 8  Bolt Group, assembled 
Fig. 9  Bolt Group, disassembled  
						

							14
UMP SUBMACHINE GUN
Assembly Group 3 
Lower receiver with trigger mechanism 
The lower receiver houses the trigger mechanism with safety/selector
levers, the backplate, the magazine well, magazine release lever and
bolt catch. The forward portion of the lower receiver is hooked to the
upper receiver. The rear portion is fastened to the upper receiver using a
removable locking pin. 
The safety/selector levers are fitted on both sides of the pistol grip.
The forward portion of the lower receiver has lugs for attachment to the
upper receiver. Behind these lugs is the magazine well with the
magazine release lever. 
Above the magazine release lever is the bolt catch. It serves to hold the
bolt rearward when the last round is fired and to release the bolt from
the open position after an empty magazine has been replaced with a
loaded magazine.The rear side of the lower receiver includes the
integrated backplate with buffer and support for the recoil spring
assembly. 
The safety/selector lever of the Navy trigger mechanism has three
positions :
Position    = Safe 
Position    = Semi Automatic fire
Position    = Fully Automatic fire 
Trigger Mechanism Variants 
Trigger mechanism for single fire, 2-round burst and fully automatic fire. 
The safety/selector lever has four positions :
Position   = Safe 
Position   = Semi Automatic fire
Position   = 2-round burst 
Position   = Fully automatic fire 
NOTE: UMP trigger mechanisms with various combinations of the
above firing modes and possibly others may also be available for the
UMP Submachine gun. 
						

							15
DESCRIPTION OF ASSEMBLY GROUPS
15
Fig. 10 Lower receiver with trigger mechanism,
backplate and magazine well
1 Trigger 7 Trigger mechanism
2 Magazine release lever 8 Backplate
3 Magazine well 9 Buffer
4 Attachment lugs 10 Support for recoil spring
5 Bolt catch 11 Safety/Selector lever
6 Release lever 12 Trigger guard 
safe                    semi-automatic fire   fully automatic fire
Fig. 11a, 11b, 11c   Positions of the safety/selector lever for safe, 
single fire, and fully automatic fire
safe                 semi-auto. fire2-round burst      fully automatic fire
Fig. 11d, 11e, 11f, 11g   Pistol grip with trigger mechanism for safe,
single fire, 2-round burst, and fully automatic fire 
						

							16
UMP SUBMACHINE GUN
Assembly Group 4
Magazine  
The magazine housing is constructed from plastic. The transparent
panels on the magazine enables its contents to be checked visually.
The magazine consists of: magazine housing, magazine floor plate,
follower, follower spring and locking plate.
Fig. 12  Magazine, complete         Fig. 13  Magazine, disassembled
1  Magazine housing
2  Magazine floor plate
3  Follower
4  Follower spring
5  Locking plate 
						

							17
ACCESSORIES
Carrying sling 
The carrying sling (Fig.14) enables the shooter
to carry the UMP in any of several ways and
ensures immediate readiness to fire from all
carrying positions (see pages 43-44).
Fig. 14 Carrying slingt  
Cleaning Kit
The cleaning kit includes:
1 Transport case 5 Oil bottle  
2 Cleaning patches 6 Bore brush
3 Cleaning brush  7 Patch holder 
4 Cleaning rod with folding handle 
Fig. 15 Cleaning Kit
Bruegger & Thomet 
Quick Connect Sound Suppressor 
To mount the suppressor, the locking lever
is depressed, the suppressor is placed over
the muzzle, and the locking lever released.
Gas pressure at the muzzle is dissipated
within the suppressor’s chamber system.
This considerably reduces muzzle blast. 
Mounting rails (MIL-STD-1913)
for aiming devices 
The mounting rail (Picatinny
Rail) is screwed onto the
molded-in hard points provided
either on top of the receiver,
below the forearm or on the right
or left sides of the forearm.
Hand Stop 
The hand stop prevents the shooter’s
hand from slipping over the muzzle. It is
screwed to the lower mounting rail on the
lower side of the forearm using a long
screw or directly to the forearm support
without a mounting rail with a short screw. 
Fig. 16 Sound Suppressor
Fig. 17  Mounting rails 
for aiming devices
Fig. 18   Hand Stop 
						

							18
HANDLING & OPERATION OF THE UMP
Magazine Loader 
The magazine loader aids in the filling of magazines. 
Fig. 19  Magazine Loader  
Filling the Magazine 
• Grasp magazine.
• Slide individual cartridges under the magazine lips one by one (Fig. 20).
• Repeat this process until the required number of cartridges has been
inserted or the magazine is full. 
Fig. 20  Filling the magazine
NOTE: Loading more than the prescribed number or rounds (i.e. 25
cartridges in a 25-round magazine) will prevent the magazine from
being inserted in the weapon with the bolt forward.
Filling the Magazine using the Magazine Loader 
• Place the magazine loader onto the magazine, depress and hold.
• Slide individual cartridge (base first) under the magazine lips (Fig. 21).
• Release the magazine loader, fully seat the cartridge.
• Repeat this process until the required number of cartridges has been
filled in.
Fig. 20 Filling the magazine using a magazine loader  
						

							19
MAGAZINE
Emptying the Magazine 
• Grasp magazine.
• With your thumb, push cartridges forward out of the magazine into
the palm of the other hand
or
•  Grasp magazine and hold it with the points of the bullets pointing
towards the bottom.
•  Use a piece of wood to slide the cartridges out of the magazine. 
Insertion and removal of magazine 
• Put the UMP on   (Safe).
• Insert magazine into the magazine well (Fig. 22). The magazine catch
has to engage audibly in the process. Tug on the magazine to ensure
it is fully engaged.
• For removal of the magazine, push magazine catch forward (Fig.23)
and remove magazine downward. 
Fig. 22 Insert magazine Fig. 23 Remove magazine 
						

							20
UMP SUBMACHINE GUN
Starting Situation 1: No magazine is present in the weapon. The bolt
is forward.
• Put the UMP on   (Safe).
• Insert the loaded magazine into the magazine well until the magazine
catch engages audibly. Tug downward to ensure it is properly seated.
• The UMP is partially loaded and with the safety on.
• Pull cocking lever backwards as far as it will go and let bolt snap back
to its forward position. In the process do not ride the cocking lever
forward.
or
• Pull cocking lever backwards as far as it will go, (Fig. 24 ) and swivel
it upwards (engage it in the indent) into the open position.
• Insert the loaded magazine into the magazine well until the magazine
catch engages audibly. Tug to check.
• With the open palm of the non-firing hand slap the cocking lever
downward and forward to chamber a round. During this process do
not ride the cocking lever forwards.
The UMP is now fully loaded and with the safety on. 
FIg. 24  Pull cocking lever backwards