Mossberg 500, 835, 590 Pump Action Shotgun Instructions Manual

							IMPORTANT “SAFETY WARNINGS” - NOTE THE SYMBOL
These safety warnings are for your protection as well as the safety of others. Disregarding
information in this manual may result in serious injury or death.
Be certain this owner’s manual is available for reference and is kept with this
firearm if transferred to another party. If manual is lost or misplaced, write
directly to Mossberg for a free replacement copy.
After performing any work on your firearm such as cleaning, adjustments,
disassembly or installation of any accessory, the firearm should be re-checked
for proper functioning before firing live ammunition.
Firearms are complicated mechanisms. Any modification, alteration, or improper
fitting of parts may result in a dangerous malfunction, damage to the firearm
and injury to the shooter and other persons. The firearm’s owner must accept
full responsibility for the correct reassembly and functioning of the firearm after
any disassembly or replacement of parts.
If you do not understand any of the material in this manual or have any
questions, contact a qualified gunsmith or O.F. Mossberg & Sons, Inc., directly.
Do not attempt to load or use any firearm until you read and understand the
information contained in its owner’s manual. Before handling your firearm, you
should learn how it operates and how to maintain it. This includes knowing its
basic parts, how the manual safety and other safety features operate, how to
safely open and close the action and how to safely load and unload ammunition from
the firearm. Improper use and handling is dangerous and could cause serious injury or
death to you or those around you. All users of the firearm must become thoroughly
familiar with the instructions in this manual.
O.F. MOSSBERG & SONS, INC.
P.O. BOX 497  •  7 GRASSO AVENUE, NORTH HAVEN, CONNECTICUT 06473
PHONE (203) 230-5300    FAX (203) 230-5420
www.mossberg.com
Safety and safe firearms handling is everyone’s responsibility.
OWNERS
MANUAL
FOR 500®, 835®
500®, 835® AND 590®
PUMP ACTION SHOTGUN
AND 590® MODEL
PUMP ACTION SHOTGUNS   
						

							As the owner of a firearm, you must undertake the full-time responsibility of
safe firearms handling for your own safety and the safety of those around you:
•  Keep all firearms and ammunition out of the reach of children.
• Store your firearms and ammunition separately.
•  Never store a loaded firearm.
•  Never leave a loaded firearm unattended.
•  Never transport a loaded firearm in a vehicle.
•  Unload your rifle when you have stopped shooting and when you have to
  climb a tree, fence, cross a slippery surface or have to transport it in a
   vehicle.
•  Do not load your rifle before you are in a place where it is safe to shoot, and
    keep  your finger off the trigger until you are ready to shoot.
•   Never shoot at water, rocks or any hard surface. Bullets may glance off such
   surfaces and cause injuries.
•  Do not use alcohol or drugs before or while handling firearms.
• Do not touch trigger while the safety button is being engaged or disengaged.
Always point the muzzle of your firearm in a safe direction, regardless of whether
the firearm is loaded or unloaded. You should become thoroughly familiar with
the function and operation of this firearm and the instructions supplied with it.
Always treat every firearm as if it were loaded. Give your firearm to someone
with the action open (bolt fully rearward) and safety fully rearward in the “ON”
(SAFE) position after you verify the firearm is unloaded. Insist on the same
procedure when receiving a firearm from someone else. Learn the location of
all the safety features of your firearm and how they operate.
Wear eye and ear protection when shooting. Shooting without proper ear
protection can cause hearing damage. The use of eye protection during any
type of shooting is important to protect your vision.
Due to the heavy recoil of a shotgun, maintain an adequate distance between the
rear of the scope and your face at all times. Be certain the scope installation does
not interfere with access to, or the proper functioning of the safety button.
We specifically disclaim any responsibility for damage or injury
whatsoever occurring in connection with, or as a result of, the use of
faulty, or non-SAAMI standard, or “remanufactured” or hand-loaded
(reloaded) ammunition. Additionally, we disclaim any responsibility for
damage or injury which results from any modifications or changes that
are not a part of the firearm as delivered from the factory.
Learn to clean your firearm thoroughly and make certain no oil, grease or other
materials are blocking the barrel. Obstructions of any kind can cause damage
to the firearm resulting in personal injury.
Practice proper firearm maintenance and safety. Make sure all exposed metal
surfaces are coated with a thin film of oil, especially after being exposed to
damp weather. (See proper section of this manual for cleaning instructions.)
Do not plug barrel or store in fabric-lined case which will absorb lubricants from
the firearms. Before using after storage, follow complete instructions stated in
this manual for refamiliarization with the firearm. A thorough inspection should
be performed before going into the field. Have your gun periodically checked
by a qualified gunsmith.
PART NO. 12173 REV. H 
						

							TABLE OF CONTENTS
Page
Operating Instructions............................................................................................  2
Mechanical Safety ...............................................................................................  2
Barrel Assembly ..................................................................................................   3,4
Magazine Capacity ..............................................................................................  4
Loading ...............................................................................................................  4-6
Firing the Shotgun ...............................................................................................  6
Unloading the Shotgun .......................................................................................  6,7
Disassembly Procedures ....................................................................................  7-10
Cleaning and Lubrication ....................................................................................  10
Assembly Procedures .........................................................................................  10-12
Function Testing ..................................................................................................  12
Sight Adjustment .................................................................................................  13
Accessory Barrels ...............................................................................................  14
Pistol Grip Installation .........................................................................................  14
Speedfeed
® Stock ...............................................................................................  15
Heat Shield ..........................................................................................................  15,16
Dual-Combo
® Stock ............................................................................................  16,17
Accu, Accu-Steel and Accu-Mag Choke Tubes ...................................................  17-19
Muzzleloader Barrels ..........................................................................................  19
Service Instructions .............................................................................................  20
Warranty Information ...........................................................................................  21
Parts List .............................................................................................................  22
Exploded View ....................................................................................................  23
Notes ...................................................................................................................  24,25
The Basic Rules of Safe Firearms Handling...............................................  Back Cover 
						

							2
OPERATING INSTRUCTIONS
Read and understand this entire manual and its safety warnings before firing the shotgun.
Remember, a firearm’s manual safety is a mechanical device which can never
replace safe gun handling practices.
Never rely on any mechanical safety device to prevent the dangers of careless
handling or pointing a firearm in an unsafe direaction.
MECHANICAL SAFETY
The safety is located on  the top rear portion of the receiver (Fig. 2) and must be manually
moved to the desired position by the shooter.
To put the safety in the “ON” (SAFE) position, the safety button must be moved
fully rearward into the safety detent. The button will now be over the red dot. The red
dot is a training aid used only to show the direction of the “ON” (SAFE) position and
should not be used as an indicator that the safety is “on” or “off” (Fig. 2). Moving the
safety button forward toward the muzzle of the gun will put the safety in the “OFF”
(FIRE) position.
ACTION RELEASE CONTROL
The action lock lever is located on the left side of the trigger housing just rearward of the
trigger guard.
The action lock lever allows the action to be unlocked and opened for inspection or
unloading without pulling the trigger. The action may be opened by depressing the lever
and pulling the forearm rearward (Fig. 3).
NOTE: During the firing, the action unlocks automatically after the hammer falls and
the action can be cycled without depressing the action lock lever.     
						

							3
BARREL ASSEMBLY
Barrels are not interchangeable between model numbers, gauge or capacity.
500, 835 and 590 barrels are interchangeable only with barrels of the same model,
gauge and capacity.
CAUTION: Never close the action or pull trigger while barrel is removed as damage
could result to the firearm.
To facilitate shipping, some models are packaged with the barrel removed. To install the
barrel in the receiver, proceed as follows:
Visually inspect the inside of the barrel to make certain it is free of any
obstructions, excessive oil or grease before installation. If you are unable to
remove all obstructions, bring the gun to a qualified gunsmith or ship it to the
authorized Product Service Center. Failure to do so may result in gun damage
and/or personal injury if the shotgun is fired.
Move the safety button fully rearward to the “ON” (SAFE) position (Fig. 2).
All Models:Depress the action lock lever, (Fig. 3) and move the forearm rearward until
the front of the bolt is in the middle of the ejection port (Fig. 7).
Caution:  Wear eye protection.
590
®/835®Unscrew the magazine cap by turning it counterclockwise.
Slide the barrel takedown mount ring over the magazine tube while guiding
the barrel extension portion of the barrel into the receiver (Fig. 4).
Gently rotate the barrel back and forth while pushing the barrel into the
receiver.
Slide the barrel into the receiver and tighten the magazine cap, finger
tight only. DO NOT use pliers or a wrench to tighten magazine cap.
If your 590/835 shotgun is equipped with a magazine spring retainer,
prior to putting on the magazine cap, assemble the magazine spring
retainer over the protruding magazine spring. Push the retainer
down-ward inside magazine tube so that the spring retainer is flush with
the magazine tube end.
Models:   
						

							4
Caution:The magazine spring exerts pressure on the retainer. Use caution when
disassembling.
To disassemble: Pry up at various points around the small hole in the
center of the magazine spring retainer. Cup hand over retainer and
magazine so as to keep spring and retainer confined. Use caution not
to bend or distort the magazine tube end and or threads.
500
® Models:Slide the barrel into the receiver and tighten the takedown screw, finger
tight only. DO NOT use pliers or a wrench to tighten the takedown screw.
A little space between the magazine tube and the takedown mount is
normal.
WARNING (all models): Check to be certain that the barrel is fully seated into the
receiver by looking through the ejection port. The barrel extension must rest firmly
against the corresponding cut in the top of the receiver as shown in Figure 4.
MAGAZINE CAPACITY
835
® Models:Total ammunition capacity (including one in the chamber) is six (6)
2-3/4 or 3 or five (5) 3-1/2 shells.
500
® Models:Total ammunition capacity (including one in the chamber) is six (6) 2-3/4
shells. Depending upon ammunition tolerance variations, total capacity may
be reduced by one round when using 3 shells.
590
® Models:Total ammunition capacity (including one in the chamber) is nine (9) 2-3/4
or six (6) 3 shells.
NOTE: To comply with U.S. migratory bird laws, six shot models are shipped with a
wooden dowel inserted in the magazine tube which limits magazine capacity
to two (2) shells.
835
® Model:To remove the dowel, first remove the barrel. Point the gun downward and
shake it back and forth lightly until the dowel falls out.
To change back to a 2-shot magazine capacity insert the dowel through the
center of the magazine spring so that it is positioned inside the coils of the
spring.
500
® Bantam Model:This Model is supplied as a single shot. An extra long wooden dowel
blocks magazine loading. After proper firearm training the dowel can
be cut to 9 to comply with appropriate laws.
500
® Model:To remove the dowel, first remove the barrel. Point gun downward and
shake it back and forth lightly until the dowel protrudes from the
takedown screw hole in the end of the magazine tube. A rubber “O”
ring on the dowel prevents it from falling out accidentally. Grasp the
dowel and pull it completely out.
LOADING
Before loading, move the safety button fully rearward (Fig. 2) to the “ON” (SAFE)
position.
During loading never allow fingers or any objects to contact the trigger. Keep the
muzzle pointed in a safe direction at all times.
Depress the action lock lever (Fig. 3) and open the action by pulling the forearm
completely rearward. 
						

							THE SHOTGUN IS NOW  LOADED! The safety button should be fully rearward in the
“ON” (SAFE) position until ready to use. Keep the muzzle pointed in a safe direction at
all times.
LOADING MAGAZINE
Load the magazine tube by turning the shotgun so that the trigger guard is facing up and the
action is closed. Push the front end of the shell into the magazine tube until the rim of the shell
snaps past the cartridge stop (Fig. 6 & 9). Never attempt to exceed the magazine capacity.
5
Inspect the chamber and bore of the barrel for any obstruction, excessive oil or grease.
The chamber is the rear portion of the barrel which contains the cartridge (Fig. 4).
Failure to do so may result  in gun damage and/or personal injury when the shotgun is
fired.
Do not load shotgun until ready to use! Unload shotgun when shooting has been
completed! The safety button should always be fully rearward in the “ON” (SAFE)
position whether the firearm is loaded or not.
Check to be certain that the ammunition selected is the same type of cartridge as
designated on the left side of the barrel.
The 835
® Models are designated to fire 12 gauge 2-3/4, 3, or 3-1/2 factory loaded
ammunition. Do not fire slugs of any type (single projectile ammunition) through the
overbored 835 Accu-Mag barrel. This barrel is designated to shoot lead or steel pellet shot
loads only. Use only 835 barrels designated specifically for slug shooting.
590
® Models handle 12 ga. 2-3/4 or 3 magnum shells. 500® Models are designed for 2-3/4
(2-1/2 .410 bore) and 3 magnum shells within gauge.
Fully rifled barrels deliver best accuracy with sabot style slugs. “Rifled” slugs and shotshells are
not recommended for use in rifled barrels.
If you wish to load the firearm with the maximum number of shells, or fire single shots, load the
first shell through the ejection port located on the right side of the receiver (Fig. 5). The shell can
be inserted directly into the chamber or placed on top of the elevator. Close the action by moving
the forearm completely forward. Be sure to leave the safety “ON” (fully rearward) until you are
ready to shoot.   
						

							6
FIRING
Discharging firearms in poorly ventilated areas, cleaning firearms, or handling
ammunition may result in exposure to lead and other substances known to cause
birth defects, reproductive harm, and other serious physical injury. Have adequate
ventilation at all times. Wash hands thoroughly after exposure.
With the shotgun pointed in a safe direction and held in the proper firing position, move the
safety forward to its “OFF” (FIRE) position. Pulling the trigger through its full travel to the rear, will
fire the shotgun.
Should the shotshell fail to fire, keep the gun pointed in a safe direction. Move the
safety button fully rearward to the “ON” (SAFE) position. Remove the misfired shotshell
and segregate from other ammunition. Do not attempt to refire a misfired round.
If at any time during firing, the report of any given round is noticeably louder or softer
than previous rounds fire, STOP! Do not load or fire additional rounds until you have
put safety in the “ON” (SAFE) position, then safely unload your firearm and inspect it
for possible damage or obstruction in the chamber or bore.
CYCLING THE ACTION
To eject a shotshell case, pull the forearm completely rearward. The spent case or unfired
shotshell will eject out of the receiver through the ejection port.
Be sure that all observers are clear of the path of ejection. Empty cases are thrown out
with significant force and could cause injury.
To chamber a live shotshell from the magazine, push the forearm fully forward.
Remember: when the magazine tube is loaded and the action is cycled, a live shotshell
will be chambered!  Always keep the safety in the “ON” (SAFE)  position until you are
actually ready to fire the shotgun.
UNLOADING
Move the safety button fully rearward (Fig. 2) to the “ON” (SAFE) position. During
unloading, never allow fingers or any object to contact the trigger. Keep the muzzle
pointed in a safe direction at all times.
Depress the action lock lever (Fig. 3) and pull the forearm rearward, slowly, until the live shotshell
is completely withdrawn and visible in the ejection port. Remove shotshell by hand.   
						

							7
Continue pulling the forearm rearward to release the next shotshell onto the elevator.
Turn the shotgun so that the ejection port faces downward to allow the released shotshell to drop
out through the ejection port.
Push the forearm completely forward, closing the bolt without a shell being chambered.
Turn the shotgun over so that the trigger guard is positioned upward and the gun
remains pointed in a safe direction.
Insert your right thumb into the opening in the bottom of the receiver and depress the cartridge
stop on the right side to release shotshells one at a time (Fig. 9). Repeat until all shotshells are
removed from the magazine tube.
Depress the action lock lever and pull the forearm completely rearward. Visually and
physically inspect chamber, elevator and magazine tube again to insure that no
shotshells remain in the shotgun.
Leave the action in the open, rearward position and the safety button fully rearward in the “ON”
(SAFE) position.
DISASSEMBLY / BARREL REMOVAL
Position the safety button fully rearward in the “ON” (SAFE) position and visually and
physically check chamber, elevator and magazine to be certain gun is loaded. Wear
eye protection during disassembly and cleaning.
Depress the action lock lever (Fig. 3) and open the action by sliding the forearm fully rearward.
Move the forearm slowly forward from the fully rearward position until the front of the bolt is in the
middle of the ejection port (Fig. 7).
CAUTION:The 590® and 835® Model magazine spring retainers and springs are under
significant spring pressure. Use caution should removal be necessary to prevent
injury to yourself or others around you.
835
®/590® Models: Unscrew the magazine cap by turning it counterclockwise.
 Remove the barrel from the receiver with a gentle back-and-forth rotational
 movement while pulling the barrel out of the receiver assembly.
500
® Models: Loosen the takedown screw by turning it counterclockwise until the screw
 threads are completely disengaged from the end of the magazine tube
 (Fig. 7).   
						

							8
Remove the barrel from the receiver with a gentle back-and-forth rotational
movement while pulling the barrel out of the receiver assembly.
TRIGGER HOUSING REMOVAL
Position the shotgun on a clean surface with the trigger guard upward. With a blunt object (no
greater than 3/16 [4.76 mm] diameter), push out the small diameter trigger housing retainer pin
located on the side of the receiver, approximately a 1/2 (12.7 mm) below the rear of the trigger
guard (Fig. 8).
Remove the trigger housing assembly by lifting the rear portion upward first.
The trigger housing is a complex assembly and must not be disassembled.
Disassembly should only be performed by the factory or a qualified gunsmith.
Do not pull the trigger and allow the hammer to fall when the trigger housing  assembly
is removed from the receiver. To do so may result in personal injury or damage to the
assembly.
CAUTION: Before performing any further disassembly, take time to study how the internal
components are arranged inside the receiver.
DISASSEMBLY OF INTERNAL RECEIVER COMPONENTS
CAUTION: Pay special attention to the position of the bolt, bolt slide and action slide bar
assembly during this portion of the disassembly, as the parts must be in the same
relationship during reassembly.
Remove the cartridge interrupter from the ejection port side and cartridge stop from the opposite
side. (It may be necessary to tap the sides of the receiver lightly to release these parts) (Fig. 9).