Heckler And Koch HK UMP45, UMP40 Operators Manual

							31
CLEANING
Normal cleaning
Performed after each firing or every twelve (12) months.
Major cleaning
Often referred to as “detailed cleaning”. Performed on an unsuppressed
UMP after 1,000 rounds (500 for a suppressed UMP) or when the
weapon is exposed to or excessively laden with sand, dust, water or
other visible contaminants or foreign matter.
• The cleaning intervals listed here are recommendations only!
• Your intervals between cleaning will vary greatly depending on many
factors to include the type of ammunition used, the environment in
which the weapon is used, and the thoroughness of your cleaning, etc.
Normal Cleaning
1. CLEAR THE WEAPON!
2. Disassemble the weapon into the major assembly groups.
Bruegger & Thomet Quick Connect Sound SuppressorUse a nylon
bristle toothbrush and rag or swab to remove all fouling from the
attachment area and locking lever of the sound suppressor. Tap the
sound suppressor lightly on a padded surface or blow it out with
compressed air to remove any loose fouling from inside the
suppressor body. (DO NOT immerse the sound suppressor in solvent
or insert any rods, brushes or patches into the sound suppressor
body! Wipe the outside of the sound suppressor off with a clean, oil-
free rag. Do not apply oil to the outside of the sound suppressor or it
will burn off during firing and obscure the operators view of the target.
Multi-purpose carrying slingThe nylon webbing and plastic com-
ponents of the multi-purpose carrying sling can be cleaned using
warm soap, water, and a soft bristled brush. Allow the sling material to
dry completely before storage or use.
Buttstock Simply remove any foreign debris from the exterior polymer
and rubber surface of the buttstock using a toothbrush, rag, swabs or
compressed air when available.
Lower receiverRemove any foreign debris from the plastic pistol grip
using a tooth-brush, rag, swabs or compressed air. Scrub the top of
the hammer, ejector and the area around the front of the ejector and
release lever with a small amount of solvent or oil to break up the
carbon fouling. Remove the loose fouling and debris by rinsing the
components in the a solvent tank or by using rags, swabs, or 
						

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UMP SUBMACHINE GUN
compressed air.
Forearm / foregripRemove any foreign debris from the forearm or
optional foregrip using a toothbrush, rag or compressed air.
Upper receiver with barrel Start with the bore and chamber.
•Bore– Apply a liberal amount of solvent to a bronze bristle bore
brush of the appropriate caliber. Always insert the bore brush from the
chamber end and push it all the way through the barrel in the direction
that the bullet travels. Pull the brush back through the barrel. DO NOT
allow the brush to stop in the bore or it may get stuck! Repeat this
in/out  procedure for a minimum of three complete trips. Remove the
bore brush and let the solvent work in the bore for a few minutes
while you clean other components.
•  Chamber – Apply a liberal amount of solvent to the appropriate bore
brush. Insert the brush through the back of the receiver into the
chamber. DO NOTpush the brush past the chamber! Work the brush
back and forth in the chamber at least three times. Remove the brush
and let the solvent go to work on the fouling for a few minutes while
you work on other components.
•Chamber face– This area is easily tackled using the special
Chamber Face brush available in the HK Field Weapons Cleaning Kit
for the UMP submachine gun. Attach this brush to the cleaning rod
and lock the handle so that the rod and brush can be turned together.
Apply a liberal amount of solvent to the bristles of the brush. Insert the
brush through the back of the receiver until it makes contact with the
area surrounding the opening to the chamber and bore. With slight
inward pressure, rotate the brush in a clockwise direction to break up
the carbon fouling built-up on the face of the chamber. Continue this
procedure until you are satisfied with your efforts.
•Upper Receiver– Apply a few drops of solvent to a toothbrush and
scrub the area around the chamber face and along the length of the
receiver rails to break-up the carbon fouling.
•Muzzle and accessory attachment  interface– Use a nylon bristle
toothbrush and a small amount of solvent to remove any fouling from
the muzzle where the sound suppressor and muzzle mounted
accessories attach. Remove all of the fouling, carbon, and visible
debris from the entire upper receiver using a solvent tank and
compressed air or swabs, patches, rags, etc. Run al least three clean
patches of the appropriate size all the way through the bore in the
direction of bullet travel to remove the loose fouling and solvent. 
						

							33
CLEANING
Bolt group
Scrub all parts of the bolt group with a toothbrush and solvent where
carbon is visible, especially around the face of the bolt and the
extractor. Do not attempt to remove the extractor for cleaning!
There is no functional need to remove the extractor for normal
cleaning. Remove the loose fouling from all parts using a rag, swabs
or compressed air.
MagazineDon’t forget the magazines! They are very important and very
often overlooked during cleaning. Many stoppages occur as a result of
improperly maintained magazines.
Apply a few drops of solvent to a toothbrush and scrub the top of the
magazine to remove any visible carbon fouling or loose debris. Pay
special attention to the front edge of the housing, feed lips, and the
follower.
Remove the solvent and loose fouling from the magazine using a rag,
swabs or compressed air.
Major Cleaning 
As mentioned earlier, Major cleaning should be performed after 1,000
rounds are fired through an unsuppressed UMP or 500 rounds through a
suppressed UMP. Major cleaning is also performed when the weapon
has been immersed in water or is laden with large amounts of visible
foreign matter or fouling.
During Major cleaning, all weapon components except the sound
suppressor and the carrying sling, should be rinsed with or immersed in
solvent and scrubbed thoroughly with a brush. This includes the
magazine and it’s parts. The components can then be dried using a rag
or swabs, though compressed air is preferable for Major cleaning.
If any assembly groups require a more thorough cleaning, an “Ultra-
Sonic” cleaning machine can be used containing any solvent that it is
safe to place your bare hands in, as a general rule. 
However, avoid placing painted surfaces such as the firing mode
markings on the lower receiver into an ultra-sonic cleaner, as this may
remove the colored markings. Further disassembly of any assembly
group(s) beyond the level described above mustbe performed by, or at
a minimum supervised by, an HK factory-trained armorer. 
						

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UMP SUBMACHINE GUN
Operator inspection
During or after cleaning the operator should inspect the weapon and it’s
components for any irregularities that may causes problems during it’s
operation. If any potential deficiencies are noted, they should be
corrected immediately and/or brought to the attention of the unit armorer.
In general, the operator should keep a watchful eye out for the following
discrepancies both in the weapon as a whole and in each assembly
group.
• Improper function
• Missing parts
• Cosmetic flaws (cracks, dents, burrs, rust, etc.)
• Improper assembly
• Loss of spring tension (where applicable)
• Unusual looseness (where applicable)
• Cracked welds
• Excessive wear
• Absence of protective finish (where applicable)
• Absence of proper lubrication
Also check these more areas where problems may begin in the UMP.
Lubrication
Any type of high-quality, medium-weight lubricant (oil) specifically
designed for use on firearms such as Break-Free (C.L.P.) Ballistol,or
Militec will work well on the HK UMP submachine gun. DO NOTuse
lubricants/cleaners that boast of their ability to penetrate metal (i.e.  
WD-40, Tri-Flow,etc.) as these substances may deaden primers.
Where and how much? 
No Lube – (surface is dry and not slippery to the touch)
• Sound suppressor body
• Sling
• Plastic components
Light Lube – (finger run across surface yields little or no lube)
• Bore and chamber
• All metal parts (except sound suppressor)
• Muzzle
• Magazine spring
• Axles of all operating controls (cocking lever, bolt
catch, safety/selector lever, magazine catch, etc.)
• Rear sight assembly 
						

							35
LUBRICATION
• All metal accessories
Medium Lube – (finger run across surface yields some lube but lube
does not run down surface when held in a vertical position)
• Bolt group with recoil spring and guide rod
Heavy Lube – (Lube runs down surface when held in a vertical
position) No heavy lube is required on the HK UMP!
•  Reapply lubrication to the bolt of the UMP periodically during firing as
it burns off from the heat. Sound suppressed weapons generate more
smoke and noxious gases especially when over lubricated.
•  Apply lubricant using a shaving brush, swabs, patches, or rag. A spray
bottle also works well using compressed air to circulate the lubricant
into all parts and to remove the excess.
Special use and maintenance of HK sound suppressed weapons
In addition to the basic maintenance instructions provided earlier, sound
suppressed weapons require additional special attention from the
operator. Consult the instructions received from the manufacturer with
the sound suppressor for additional guidance.
All weapons with sound suppressors require more cleaning than the
same type of weapon without a sound suppressor. This is because the
sound suppressor is designed to capture or “suppress” the expanding
propellant gases that exit the muzzle of the weapon behind the
projectile. These gases exit the weapon at a supersonic velocity causing
a “muzzle blast”. The sound suppressor captures these propellant
gases, contains them within a series of baffles or chambers and allows
them to escape at a slower velocity thus eliminating the muzzle blast.
At the same time that the gases are contained, so is the carbon fouling
and propellant debris that would normally be blown out of an
unsuppressed weapon with the propellant gases. More fouling and
debris stays behind in a sound suppressed weapon and thus there is
more for the operator to remove during his cleaning.
In order to be effective, a sound suppressed weapon must also provide
some means to reduce or eliminate the supersonic “crack“ of the
projectile as it leaves the muzzle at a supersonic velocity (above 1,088
feet/second at sea level). 
This can be accomplished in two ways. One. By venting gases from 
						

							36
UMP SUBMACHINE GUN
behind the projectile as it passes through the bore and sound suppressor
thus lowering the exit velocity of the bullet below 1,088 feet/second. 
Or two, by firing ammunition in the weapon that is down-loaded to a
velocity below the supersonic range. This is the method used in the HK
UMP submachine gun. For this reason this ammunition is termed
“subsonic” and usually falls into the range between 875 – 1,050
feet/second. Both methods are effective but each has it’s own
disadvantages and advantages.
There are two different styles of sound suppressors available for use on
the UMP submachine gun, a quick connect aluminum or stainless steel
sound suppressor. 
Both versions are of the “wipeless” design, meaning they have no
rubber or synthetic membranes (wipes) that the bullet must penetrate.
The projectile does not touch any portion of the wipeless sound
suppressor. Wipeless designs are far more durable than other designs
and generally give the best accuracy results.
UMP with quick connect sound suppressor
• The HK UMP submachine guns are designed to be fired using
supersonic or subsonic ammunition with any weight projectile and with
or without the sound suppressor attached. 
• The Aluminum Bruegger & Thomet Quick Connect UMP .45 caliber
sound suppressor is 6.70 inches long and weighs .99 pounds. It is
intended to be used with subsonic ammunition for maximum sound
suppression. The UMP does not have a vented barrel as is found
on the HK MP5SDand therefore does not lower the velocity of the
ammunition fired in it. These quick connect sound suppressors can be
used with supersonic ammunition but the supersonic “crack“ of the
projectile will still remain even though the sound suppressor does
eliminate the “muzzle blast” caused by the propellant gases. Other
sound suppressors are available for use on the UMP, contact HK for
additional guidance. 
• Accuracy from the quick attach sound suppressor is excellent, often
better than the weapon without the sound suppressor attached,
though there is sometimes a slight change in zero when the sound
suppressor is attached. This is mostly due to the longer distance that
the projectile must pass through (similar to firing through a longer
barrel) on it’s way to the target.
• Effectiveness and service life of sound suppressors varies greatly due
to countless variables. Some of these variables include the type and
quantity of ammunition used, the predominant mode of fire used, the
operational environment in which the weapons are employed, etc. 
						

							37
SOUND SUPPRESSOR
Generally, the aluminum Bruegger & Thomet UMP sound
suppressors when used with the recommended ammunition provide
20–25 decibels (dBA) sound reduction when compared to an
unsuppressed weapon.
• An aluminum sound suppressor will generally maintain its
effectiveness to 20,000 rounds; stainless steel suppressors to 40,000
rounds or more.
•  Older sound suppressors can be replaced by the operator for a
reasonable cost. Many teams will keep the older sound suppressor for
training and maintain the newer one for operational use where peak
performance is desired.
Observe the following recommendations
• DO NOT attempt to open the sealed sound suppressor body
• DO NOT allow the sound suppressor to loosen during use. 
• DO NOT use any form of tool or wrench to install or remove the
sound suppressor. 
• Always tug forward on the UMP sound suppressor after mounting to
ensure that it is properly attached.
• If the sound suppressor will not detach from the weapon, consult the
section entitled “Normal Cleaning” of the sound suppressor or call
Heckler & Koch for guidance.
• DO NOT fire the UMP with the aluminum sound suppressor full of
water. Allow the water to drain from the sound suppressor before
attempting to fire the weapon.
• DO NOT attempt to fire the weapon if the sound suppressor has been
dented or damaged or there is damage around the exit hole or if the
sound suppressor fits loosely on the weapon.
• DO NOT insert anything into the body of the sound suppressor such
as a cleaning rod or brush.
• DO NOT add to or fire the weapon with oil, grease or any foreign
matter inside unless directed to by the manufacturer of the specific
sound suppressor.
• Keep the muzzle and attachment interface for the sound suppressors
and muzzle mounted accessories as clean as possible at all times to
insure that the sound suppressor and accessories can be easily
attached and detached when required. Clean the muzzle with a nylon
toothbrush or patch soaked in oil or solvent during each cleaning.
Lightly lube the muzzle once it is clean. A dirty muzzle can make it
very difficult to attach and detach the sound suppressor. 
						

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UMP SUBMACHINE GUN
Ammunition
The UMP submachine gun was designed to use ammunition designed to
NATO or SAAMI specifications. Like an automobile engine, you cannot
expect top performance by using poor quality fuel. The same applies to
firearms. There are a number of general considerations that should be
made when choosing the type of ammunition you plan to use in the
UMP.
DO USE
• Ammunition of the appropriate caliber and of recent manufacture
• Clean burning ammunition
• Non-corrosive ammunition
• Jacketed Hollow Point (JHP), “Silver-Tip”, ball, truncated cone, “Hydra
Shok”, +P, etc.
• Limited quantities of .45 Super ammunition in the UMP45 model
DO NOT USE
• Reloads or remanufactured ammunition. Beware of military surplus,
foreign or outdated ammunition.
• Non-jacketed or exposed lead ammunition
• Corrosive ammunition (primer and/or propellant)
• Any ammunition that exceeds NATO or S.A.A.M.I. pressure limits
• Empty cases as “dummy“ (inert) rounds, as damage may result to the
weapon, especially the synthetic magazines employed in the UMP.
Use complete dummy rounds available for training purposes.
• Aluminum cased ammunition (i.e. CCI Blazer) in the UMP40.
Stoppages 
In the event of stoppages on the UMP, the weapon is to be considered
loaded until the actual cause of the stoppage has been determined. 
During the elimination of stoppages, safety precautions are to be taken
into account. 
In the event of stoppages on the UMP, for example the cartridge fired
from the UMP is not ignited, the bolt assembly does not close
completely, or the spent cartridge case is not ejected, the following
immediate steps have to be taken: 
1. Put the UMP on   (Safe).
2. Remove the magazine.
3. Unload the UMP.
4. Ensure that barrel, cartridge chamber and receiver are free of 
obstructions. 
						

							39
TROUBLESHOOTING
5. Next, determine and eliminate the cause of the stoppage. The 
items indicated in the following tables do not cover all stoppages
theoretically possible. A given stoppage may also have been caused
by other reasons than the ones indicated. 
Stoppage Cause Remedy
Cartridge not ignited Ammunition fault Recock UMP
(Dud round)
Firing pin damaged Take UMP to 
or broken maintenance shop
Hammer spring damaged  Take UMP to 
damaged or broken maintenance shop
Bolt did not stay open on Cartridge case stuck in Unload. Retract bolt to
the last shot chamber  because it is  eject spent case. Clean
deformed or the chamber if fouled. If required take
is dirty UMP to maintenance shop
Cartridge case not  Chamber is dirty. Clean cartridge chamber. 
extracted or ejected
Extractor broken. Take UMP to 
maintenance shop
Ejector damaged Take UMP to
maintenance shop
Insufficient bolt recoil Unload. Retract load via
cocking lever to eject spent
case. Check for smooth
movement of bolt and 
check chamber for fouling.
Clean if required. 
						

							40
UMP SUBMACHINE GUN
Stoppage Cause Remedy
No cartridge fed by bolt. Magazine not properly Insert magazine properly.
inserted.
Magazine loose Check magazine catch and 
notch on magazine. If 
required  take UMP to 
maintenance shop.
Follower spring lame Replace magazine or 
follower spring and take to
maintenance shop.
Magazine lips damaged Replace magazine or
magazine housing and 
take the damaged one to 
maintenance shop
Bolt not fully closed. Cartridge chamber dirty Clean cartridge chamber.
Cartridge not fully fed.
Cartridge damaged Recock
Recoil spring lame Take UMP to  maintenance
shop
Improperly cocked Allow cocking lever to snap
forward. On releasing 
cocking lever do not ride it
forward.
Bolt does not stay open Magazine spring lame. Replace magazine and 
after last shot take damaged one to the
maintenance shop
Catch damaged Take UMP to maintenance 
shop.
Magazine stuck in Magazine damaged Replace magazine spring
magazine well and take damaged one to 
to the maintenance shop
Magazine catch defective Take UMP to maintenance
shop.