K31 Bolt Disassembly Guide by Roy Headrick

Pull bolt open. Press down on bolt release lever and
withdraw bolt. 

The K31 bolt as removed from rifle. Note the bolt flange with its slots 90 degrees apart.

Wipe off surface oil. Hold the bolt
body and operating bar in the left hand (apologies to
lefties), then with the right hand, pull back on the
cocking/safety ring until the sear at the bottom
clears, and rotate 45 degrees clockwise, halfway
between "Safe" and "Fire". Ease the ring forward to
rest the sear on the rear face of the bolt flange.

Cocking/safety ring in the 45 degree disassembly position. Detail exaggerated (crudely) by writer.
Locking lugs are still horizontal and operating bar still back.

Rotate locking lugs 90 degrees to the right, allowing
the action bar to go forward.

Locking lugs rotated, operating bar forward.

Lift the front of the operating bar slightly away from
the bolt body, disengaging the lug from the cam
grooves in the bolt body. Slide the bar forward, out
of the slot in the bolt flange.

Operating bar coming off.

Note the alignment of the cam groove in the outer bolt 
body with the straight groove in the inner bolt body, 
and that you can see down into the firing pin channel. 
The ejector cuts in the inner bolt face and the outer bolt 
body line up. 

Grasp the safety ring again, rotate back to the "fire"
position, and allow firing pin to ease forward. 

Cam groove "C" with inner groove beneath. Firing pin is forward.

Push in against the inner bolt face with thumb, and rotate
inner bolt face 90 degrees, either way. (It may help
to pull the safety ring back just a bit.) Now pull the
front half of the bolt, inner and outer together,
forward off the back part of the bolt. The bolt
face/inner half can now be pulled out of the locking
lug/outer half.

Bolt face/inner half "I". Locking lugs/outer half "O". Back part of bolt "B".

Note the two little lugs at the rear of the inner half
- that's what held it together. You freed them from
their seats when you pushed the bolt face with your
thumb and turned it.

The lugs that hold inner & outer halves together.

End view, showing the matching slots in inner bolt
face and outer bolt lugs, for the ejector.

Holding the back part of the bolt in the left hand,
push back against the coils of the firing pin spring
with the right fingers (Better wipe off any oil
first). When the end of the spring clears its seat on
the firing pin tip, trap the spring with the left
fingers, and free sideways the doll's head joint
holding the tip to the pin.

Disassembling firing pin tip "T".

 GENTLY ease the spring tension off, and remove the spring. Pull the firing pin out backwards by the ring.

Firing pin "P", spring "S", tip "T", and bolt back part "B".

Shows extractor "E", also inner groove "G" and lugs "L".

The extractor can be removed by lifting its hook end
up away from the bolt face until it is just clear
underneath, and inserting a thin screwdriver tip or a
junky knife blade underneath to hold it away. With a
small hammer & punch, tap gently on the rear, rounded
end of the extractor, moving it forward until free.

Extractor, from above.

Back end of extractor, moving forward.

Out it goes! Note the bend, for spring tension.

NOW, clean and dry everything, and spend a little time
dry-fitting all the parts together (without springs)
to see how the parts interlock and interact. Pretty
neat design & workmanship, huh?

REASSEMBLY: "Reassemble in reverse" is just a little
bit of a cop-out, so here goes the long form-
Barely start the extractor back into its place, press
the center of the extractor down against the bolt
body, then push or drive it back into place. Lightly
oil the shaft of the firing pin & ring, and slip it
into the back part of the bolt, in the "Fire"
position, and all the way forward. Place the firing
pin spring down over the pin. Hold the rear bolt half
in the left hand, and with the right fingers compress
the firing pin spring down on the pin - CAREFULLY!

Don't let it point at your face, or under the freezer.

Trap the compressed spring with your left fingers, and
replace the firing pin tip with the right hand. Let 
the spring off gently, and be sure everything is 
centered up. Put a drop or two of light oil on the 
coils. Pull back on the ring, and put it in that
45-degree position between "safe" and "fire", and rest
the sear against the flange. Lightly oil the exterior
of the inner bolt half, and slip the two front halves
together, aligning the ejector cuts. Insert the front
half assembly into the rear half, rotating 'til it
goes all the way. Push in on the boltface with your
thumb lightly, and rotate into the locked position.
(There is no snick-together, tactile stop. You just
have to stop at the right place - the extractor should
wind up on top, the cam groove and inner straight
groove on the right, the ejector cuts and firing pin
sear on the bottom.) 

Now, insert the back end of the operating bar into its
slot in the flange, and slip the lug on the front end
into the bolt grooves - the bar should be parallel
with the bolt body. Holding the bar in place, rotate
the ring back to the "Fire" position and ease forward.
Lube the operating rod lug and cam groove, and the
bolt locking lugs, and replace the bolt in the
receiver. You will have to push down on the bolt
release lever, and on the magazine follower. 
If the bolt should come "uncocked" in your hand, pull 
the ring back to the 45 degree position, be sure the 
bolt locking lugs go back to horizontal, and the 
operating bar lug rests in the little notch at the 
rear of the cam groove, then put the ring back to


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