Ruger Mark III Instruction Manual

Always unload a firearm
before cleaning, lubrication,
disassembly or assembly.
2. Insert a blunt, ‘pointed’ instrument in the oval recess of the mainspring
housing (at the back of the grip) and swing the housing latch open like the
blade of a pocket knife. (Some users find that a paper clip, looped over the
latch, is an ideal ‘instrument’ for this phase of disassembly.)
3. Swing the entire housing outward on its pivot and pull downward, removing
the mainspring housing and bolt stop pin. With new pistols...

22
If you cannot place the hammer in the horizontal
position, it is most likely because the hammer
strut is trapped behind the crosspin (see Figure 7
– not applicable to 22/45 models).  If this occurs,
lift the hammer to free the hammer strut from
behind the crosspin and then move the hammer
into the horizontal position.
If the hammer has been rotated too far forward, it
also may be difficult to rotate backwards. Inserting
the empty
magazine fully into the magazine well
will allow the hammer to rotate...

4. Fully insert the emptymagazine back
into the magazine well. Point the muzzle up
in a safe direction and pull the trigger.
Gravity should cause the hammer to return
to the cocked position if it became dislodged
in step 3 (see Figure 9).  If not, reach into
the rear of the receiver and push the
hammer back down flat (into the horizontal
position). When the hammer is in this
position, remove the empty magazine.
5. NOTE: Before sliding the bolt into the
receiver, BE CERTAIN that the firing pin stop
(part...

8. The housing latch can now be snapped shut,
completing assembly.  (See Figure 14.)  Spring
pressure should be felt just before the housing is
fully shut if the internal parts are correctly
aligned. 
9. To determine if reassembly was performed
correctly, pull the bolt backward and verify that
it opens fully.  If not, open the latch and repeat
steps 6 - 8, above.  
10. Replace empty
magazine, point pistol in a
safe direction and pull the trigger to uncock the gun. Guns should not be stored
loaded or...

MAGAZINE NOMENCLATURE
MAGAZINE DISASSEMBLY
TO DISASSEMBLE MAGAZINE: Withdraw magazine from pistol and remove all
cartridges (check chamber to be certain no cartridge remains in it).Hold
magazine upside down in left hand so that the hole in the Magazine Blockis
accessible.
1. With right hand, insert drift punch in hole and depress Magazine Block
Retaining Plungerapproximately 1/4.
2. Slide Magazine Blockforward slowly BEING VERY CAREFUL TO KEEP
PLUNGER AND SPRING UNDER CONTROL. If not contained, these...

26
MAGAZINE DISASSEMBLY
DAMAGED, NON-STANDARD, OR IMPROPERLY
ASSEMBLED MAGAZINES SHOULD NOT BE USED.
THEY CAN CAUSE THE PISTOL TO MALFUNCTION.
CARE AND CLEANING
Make Sure Gun is Unloaded!
Before cleaning, be certain the pistol and its magazine contain no cartridges.
(See “To Unload,” p. 16.)
At regular intervals, or whenever the pistol has been exposed to sand, dust,
extreme humidity, condensation, immersion in water, or other adverse
conditions, disassemble, clean, and oil it. Proper periodic...

STORAGE
GUNS SHOULD NOT BE STORED LOADED!
Do notkeep the pistol stored in a leather holster or case. Leather attracts
moisture, even though the holster or case may appear to be perfectly dry.
TO RENDER THE PISTOL INOPERATIVE FOR SAFE STORAGE
Be certain that the muzzle is pointed in a safe direction and that the safety is
“on” (S) if the pistol is cocked. Remove the magazine and carefully check it to
verify that it is completely empty. Draw the bolt fully rearward and visually
inspect the chamber to be...

28
Using a paper clip or similar non-marring tool, pull down on the main spring
housing latch located at the lower rear of the pistol grip. Swing the main spring
housing upward. With the pistol pointed upward, pull the trigger. Now invert the
pistol so that it is pointing downward. Keeping the pistol pointing downward
swing the main spring housing back in to the pistol grip and push the latch back
into the main spring housing until it is flush with the pistol grip.
When assembled in this manner, it...

SIGHT ADJUSTMENT
The Standard RUGER®MARK IIIpistol is equipped with a rear sight which
is adjustable for windage only. The rear sight can be drifted laterally in its
dovetail on the top of the slide by tapping it with a wooden or plastic headed
hammer or similar implement. The front sight is fixed. Target models are
equipped with adjustable sights. Turning the top (elevation) sight adjustment
screw clockwise lowers
the impact of the shot. Turning the horizontal (windage)
sight adjustment screw clockwise...

Disassemble one ring and reassemble over the scope body between the turret and
the eyepiece so that the clamp nut (D-73) is positioned to the right of the scope.
Install the four top screws. Do not tighten.
Disassemble the other ring and install it on the forward section of the scope tube
with the clamp nut positioned to the right of the scope. Install the four top
screws. Again, do not tighten.
Assemble the rings to the scope base with the locating “tabs” engaging the
recesses in the top surface of the...