Mossberg 500, 835, 590 Pump Action Shotgun Instructions Manual

9
Move the forearm/action slide assembly rearward so that the bolt assembly and bolt slide are
three quarters of the way rearward. When the bottom of the bolt slide is aligned with the
clearance cuts in the sides of the receiver, lift the bolt slide upward and out of the receiver
(Fig. 10).
Remove the bolt assembly by sliding it forward and out of the receiver assembly through the
barrel opening at the front of the receiver (Fig. 11-A).
NOTE: The safety button located on the upper rear of the receiver...

10
Remove the forearm/action slide assembly by sliding it forward and off the magazine tube.
CAUTION: Field disassembly is now complete! The shotgun should not be
disassembled further for routine cleaning or maintenance. Further disassembly should
only be performed at the factory or by a qualified gunsmith.
CLEANING AND LUBRICATION
With proper care, your Mossberg
® shotgun will  provide you with years of dependable service.
Your firearm should be inspected and cleaned periodically to insure that it...

11
Assemble the elevator by squeezing the arms together sufficiently to position them in the
receiver so that the buttons on the elevator fit into the corresponding (1/4 [6.4 mm]) diameter
holes in the receiver (Fig. 11).
Pivot the elevator so that the forward portion of the elevator is even with the outside edge of the
cavity in the receiver.
Insert the rear of the bolt assembly, with its bolt lock downwards toward the front inside top of the
receiver, into the barrel opening of the receiver. Depress...

12
TRIGGER HOUSING ASSEMBLY INSTALLATION
NOTE:Hammer must be in the fully-cocked position to allow the trigger housing to be
inserted in the receiver.
Hold the cartridge stop and cartridge interrupter in place firmly against the receiver walls with
one hand and grasp the trigger housing assembly with the other (Fig. 9).
Insert the lugs, on each side of the front corner of the trigger housing into the slots on each side
of the receiver (Fig. 14-A), then ease the rear of the housing assembly down and into...

IF YOUR FIREARM DOES NOT PERFORM AS DESCRIBED IN ANY OF THE
ABOVE STEPS, CONTACT O.F. MOSSBERG & SONS, INC., IMMEDIATELY.
DO NOT ATTEMPT TO USE THE FIREARM.
SIGHT ADJUSTMENTS
BEFORE MAKING ANY SIGHT ADJUSTMENTS:
a. Move the safety button fully rearward to the  “ON” (SAFE) position and keep
muzzle pointed in a safe direction.
b. Open the action, visually and physically check chamber, elevator and magazine
tube to be certain the firearm is unloaded.
RIFLE SIGHT ADJUSTMENTS
IRON SIGHTS:
Elevation may be...

14
MOSSBERG ACCESSORY BARRELS
Accessory barrels are interchangeable only within specific model, gauge and
magazine capacity.
500
® Models:HS410 barrels are not interchangeable with standard Model 500 .410 bore
sporting barrels.
PISTOL GRIP INSTALLATION
BEFORE PERFORMING ANY DISASSEMBLY OR ASSEMBLY PROCEDURE:
a. Move the safety button fully rearward to the  “ON” (SAFE) position and keep
muzzle pointed in a safe direction.
b. Open the action, visually and phsycially check chamber, elevator and magazine...

15
SPEEDFEED STOCK
BEFORE CLEANING OR REMOVING THE SPEEDFEED STOCK:
a.    Move the safety button fully rearward to the “ON” (SAFE) position and keep
muzzle pointed in a safe direction.
b. Open the action, visually and physically check chamber, elevator and magazine
tube to be certain the firearm is unloaded.
The stock springs and followers should be removed periodically and the tube and
parts cleaned to remove debris. Do not lubricate these parts.
The recoil pad on the speedfeed stock is under spring...

16
2) Carefully remove front sight by turning it counterclockwise. Take precautions to insure you
do not damage the barrel finish.
3) Slide heat shield onto barrel from muzzle end. Large ring on heat shield is positioned
towards rear of barrel.
4) With the heat shield on the barrel, use a small padded “C” clamp or a vise, to close the
forward clamp of the heat shield.
5) Position the appropriate length plastic spacer or optional bushing style spacers between
the forward clamp. Insert the two screws and...

To Change Removable Combs:
1) Using a 3/16 inch Allen head wrench (supplied) unscrew and remove the comb retaining
screw found at the top center of the removable comb.
2) Place the desired comb into position. Insert the comb retaining screw and snug-tighten.
Do not overtighten as this will damage the internal assembly components.
ACCU, ACCU-STEEL, ACCU-MAG CHOKE TUBES
BEFORE REMOVING OR INSTALLING ANY CHOKE TUBE:
a. Move the safety button fully rearward to the  “ON” (SAFE) position and keep
muzzle...

ACCU-STEEL CHOKE TUBES
ACCU-STEEL TUBES - have been specifically designed for exceptional endurance and
controlled patterning of steel shot.
These tubes should provide the best pattern results for the steel shot sizes stamped on each
tube.
Lead shot may be used with ACCU-STEEL tubes; however, pattern tests should be made to
compare the pattern change.
To  remove choke tube, loosen with the choke wrech provided, turning counterclockwise. When
loose, remove completely with fingers, put choke on a clean dry...