Didn't realize that Stickey had a post so wrote this out.
OK JK, now that I know you have everything aft of the bolt in your hands,
here's the skit:
BTW all the mechanism is illustrated Ref: PP 114/115 Ross Rifle Story... Get a
copy! Bob McKormick, $120 +or -
castregd@primus.ca
Remove the cross pin holding the cocking piece onto the firing pin and thus
compressing the firing pin spring et al.
In this case (only) you do it by clamping the cocking piece in a vice
(w/protection) and threading a piece of wire through the hole in the protruding
rear of the F/pin, and having made a loop big enough, pull the pressure off the
cross pin and push/tap out with a drift.
Now the spring wants to trap the wire and you will have to compress the spring
from the other end and remove the wire.
The whole works should come apart and MAKE NOTE of the two pieces (now) on top
of the spring.
On the (very) top of the spring there is a threaded "nut" with two bosses on the
top and two indents in the bottom.
Next, underneath, there SHOULD be a circular washer with a "bumpout" on one
edge, and with two ridges (one each side) on the top surface.
Now look inside the bolt.
STOP PRESS:
To get the bolt out of the housing, (NOTE THAT THE GAS VENT IS ON PORT (left) AS
YOU LOOK FORWARD on a fully compressed bolt assembly) put screw driver under
extractor head and turn slightly to disengage from bolt and pull out forward.
Pull out (unscrew)bolt head.
Now with the bolt in your hands, you will see threads AND a vertical indent to
take the bump on the washer (to keep the washer from turning as one threads in
the "nut)
The idea is that the washer engages the bolt, and it's ridges keep the "nut"
from unwinding.
Sometimes the ridges wear off, and sometimes the bump on the periphery is worn
or broken off, and if that is the case, the nut can back out.
That is the result with you now, so do a THOROUGH inspection before reassembly.
To put it all together one needs a "dog wrench" (my term) that will engage the
two bosses on the top of the "nut", and go on over the protruding firing pin,
and allow you to screw it back in (bump, bump,...), on top of the "locking"
washer, flush with the back of the bolt.
I have a stepped and drilled lugged nut, and "lugged screw driver with a hollow
handle, but you can make up a "tool" out of a piece of small steel tube, and cut
notches with a file and use vice grips to turn it on/in.
Grease the ridge to nut interface to avoid any (further damage) although they
are both hardened.
OK, the (complete) bolt is ready to put back in the housing.
Thread the bolt into the housing and PLAY (and PLAY) with it until the gas "port
is on port" (that's how you will always remember what is right) when it is FULLY
HOME. Now reinstall extractor. (reverse above).
Align the indent in the firing pin at 90 degrees(at the bottom) to the bolt.
('cause you are going to put the retaining cross pin through the cocking piece
and through the indent and you will need it all lined up or it won't go).
Place cocking piece in the bolt with chamfer face aft (sorry) and insert the
wire you saved from before.
Clamp the bolt carrier handle down, in a (protected) vice and using all three of
your hands pull the firing pin and cocking piece back until it clears the
carrier and insert the cross pin (without letting it fall on the floor).
Extend bolt (gas port up) and place in rifle.
#### and snap 10 times to build confidence of a job well done and
REMEMBER...ALWAYS fire the first round (from a new rifle or after working on
one) with the rifle at your side with action facing away.
Good luck
Cheers
Oldguncrank