Crosman Model 600 Disassembly, Part 3

On I go...

I pushed the cross pin out, keeping the punch in the hole. The buffer assembly is under a little bit of spring pressure, so I kept my thumb over it when I withdrew the punch.

The cross pin.

The buffer comes out.

The buffer and hammer spring.

Now to remove the ring (or cam ring).

I pushed against the hammer and jiggled the ring off.

Then rotated the ring so the small end could clear the slot.

The ring.

This is the main problem the pistol has. There's a lot of clearance between the square hole and the cam.

You can see how chewed up it is. I'm not entirely sure what I'll do about this yet. I could try making a new one fron scratch, or sleeving this one. Or finding a replacement somewhere. We'll see.

Then the hammer comes out.

There's an internal o-ring.

Next I inserted my largest screwdriver into the front of the tube. and unscrewed the valve front. I will be making a special tool for this, but with care the screwdriver works fine.

I found I had to reinsert a punch into the cross pin hole to get enough torque to loosen the valve front. Otherwise the tube just spins.

The valve front comes out.

The valve front parts, screen, felt filter, washer and spacer.

Then the valve stem and spring.

I pushed the tube out the back of the frame.

The tube and frame.

The rear valve body is retained by two blind dowel "retainer" pins that are threaded internally. I threaded a screw into them and pulled them out.

Just a close up.

A retainer pin.

Notice the o-ring at the transfer port.

The rear valve body pushed out.

Interesting off-white o-ring seal.

Then I removed the o-ring from the port. That's everything disassembled that needed it.

Next I'll be disassembling the other 600 I have and scavenging what parts it needs to make at least one fully functioning pistol, as well as measuring what I hope is an unworn ring (cam ring) so I can duplicate it. The other 600's frame has a broken trigger guard and the pistol leaks slowly but feeds and functions fine. We'll see. I'll put up pics of any differences between the two as well.

Crosman Model 600 Disassembly, Part 2

On I go...

Next I removed the set screw that holds the barrel in place.

Which slides out the front of the frame.

It's easy to put a longer barrel on, as you can see.

Next I removed the safety.

The safety assembly.

I took a deep breath and removed the cover plate for the trigger.

Parts stuck to the plate which caused a few moments of head scratching.

Here's what it should look like.

Another view. You can see a line on the conical boss where one of the spring ends should rest.

And another view. You can't have too many views of complex mechanisms...There are variations on the trigger mechanism components as well between different years of the 600.

The pawl and link.

The sear.

The hammer sear?

The trigger.

Next I removed the slide screw.

And slid the slide out.

There was just a spring here when there should have been a ball and possibly a spring guide pin.
That it was bent tells me someone tried to make up for the space of a lost ball.

The slide is slightly dovetailed into the frame.

More to come...

Crosman Model 600 Disassembly, Part 1

Derrick sent me a Crosman model 600 pistol to play with. It wouldn't feed reliably and was in poor shape, generally.

He shipped it with the grips already removed. Not that it would have added much to the process.

The 600 is a true semi-automatic pellet pistol, 10 round in line magazine.

I removed the piercing cap. There are several variations of this and I'll show another one later when I disassemble a second 600 I recently acquired.

I removed the rear sight screw.

A tiny ball bearing provides the detent for the sight elevation.

Sight components.

The rear cover is up next.

Held on by a screw and lock washer.

It retains the magazine spring.

I removed the spring and pulled the follower towards the rear. The knob is retained by an allen set screw.

With the knob removed the follower comes out. Here are the parts so far.

Here you can see the set screw, knob and follower.

The feed arm on this pistol is retained by one set screw. On others it may be retained by two.

With the screw removed the cam slides out the magazine tube.

The feed arm, cam and set screw.

The feed arm is a bit scarred up, likely due to inexpert unjamming technique (brute force with a screw driver).

More to come...

A Rear Sight Plate for the Weihrauch 35E

Back to the HW 35.

With the diopter sight installed, the rear sight holes in the base block stood empty. Beeman used to offer a steel plate to cover the holes and sight base. I think the last cost on it was around $30. Due to Beeman's recent sale, I have no idea if this part will still be available for much longer.

Here, the holes are temporarily filled with brass set screws. They're some crazy ultra-fine metric size. They're M5 X 0.5 mm. "Normal" M5 bolts have the threads 0.8 mm apart. Good luck finding set screws in this size. I got a couple from Chuck at Precision Airgun. If I hadn't found any, it would be a simple matter to make some using a thread cutting die. I found a small pile of the dies at Kromhard Twist Drill Company this week--I think the die costs about $11 . Kromhard is a great source for hard to find taps and dies. It's their specialty and they make every effort to carry thread cutting tools in sizes we don't even know exist. Non-standard seems to be THE standard in the gun industry.

Dug out a strip of steel from the scrap box. It's almost the exact width and length needed. It's 0.510" wide and about 3.3" long.

A bit of Dykem layout fluid.

Dialed a caliper to half the 0.510" width...

Set one jaw on a long edge and slid the caliper across the Dykem coated face, scratching a fine line dead center. Center located.

Removed the brass setscrews.

Couldn't find any M5 x .5 mm flat head screws. Elected to turn the brass set screws into threaded bushings. The Beeman plate uses the same technique.

The rearmost set screw stood proud by a few thousandths. Chucked it in the 3-jaw on the Taig lathe. Faced it down then spotted the center.

Through drilled with a #47 drill bit.

Followed up with a #3-48 tap.

Reinstalled into the rear hole. Same procedure to the front set screw. I worked each set screw separately to maintain center.

Measured the hole spacing between the two bushings. (The holes are 1.565" apart.) Used a 3X magnifier to ensure I was on the scribed line. Marked first with a transfer punch then followed with a spring loaded center punch for a deeper mark.

Spotted both marks on the drill press.

Then clearance drilled with a #40 bit (0.098").

The #3-48's just fit.

Testing, testing....

Countersunk the screw heads.

Wire brushed.

Need to square the ends.

A scrap block of steel. It's got clean 90 degree corners, so the long edge of my plate is lined up and the end is left just slightly higher than the block.

Filed down until flush with the block.

A file card and some chalk help keep the file from loading.

Flipped and repeated on the opposite end.

At this point, it's just a steel rectangle. I hand filed the front and rear to make a smooth transition to the base block.

The front gets a longer taper.

Started at 180 grit.

Finished sanding with a steel block wrapped in 500 grit emery cloth. This gave good control over the scratch pattern.



Some Mothers Mag & Aluminum Polish on the back of a 10 meter target was used to bring the plate to an almost mirror finish.

Final polish on the tapered ends was sped up with a buffing wheel.

Polished out and then hit it with Birchwood Casey Super Blue.

Done deal.

Looks OK.

I'm about finished with the HW35 for now. Did find an old Flaig Ace trigger shoe that seems to match the curve and width of the blade, but it's too long. Think I'm going to either mill or grind it down to fit rather than make one from scratch. Doesn't sound too exciting, but I'll take a few pics.

Random: Typically, I try to use metric on metric threaded guns and Imperial on--well, you get the idea. Used the #3-48's because I had some and I was snowed in today. If I'd had flat head M2.5 X 0.45 mm, I'd have gone that route.

Some More Notes on Reassembling a Crosman 140

Just a couple of pictures of what I did to get it working...

I chucked up the breech cap in the Taig lathe.

Filed and sanded smooth. Notice the number 114 on the end...

The two o rings in the valve cap were dry and split when I removed them.

I replaced the square ring with a 008 o-ring.

And the other with a 011

Likewise the valve body got a 012.

And a 111.

Pushing that knurled pin back in with an aluminum c-clamp.

I decided to chuck the transfer port seal in favor of a piece of 1/4" nylon tubing.

I hit the breech cover and breech with some Oxpho blue.

I should have done that cap in the main tube too. Oh well.

The 008 o-ring leaked, so I tried a 4mm x 2mm inside the valve cap. Worked better. It leaks down if left pumped for 48 hours, but not 24. Go figure. I know the last time I used an o-ring I said I'd order in some square seals (Quattro rings) but I never did. Maybe I will now. Anyway it pumps up and shoots. Too rainy to Chrony it but it feels good.
[Update] Ran some shots over the chronograph, got an average of 614 fps with 10 pumps, 14.3 gr. Crosman Premiers.

Crosman Model 140 Disassembly, Part 2

On I go...

With the bolt removed I was able to remove the other breech screw.

And the barrel and breech came off. Unlike the previous 140 the barrel was solidly joined to the breech.

The transfer port seal was really messed up.

Note the stamping "M140" HAWTHORNE", etc...

There's a pressed in threaded bushing that I had to remove. I punched it out. Later I would realize that my roll pin pusher works really well for this.

It's straight knurled.

Probably the biggest pain in disassembling the gun.

The tube cap (Sear Block Stop) comes out under a small amount of spring force.

Nothing fancy.

The hammer, "small tube plug" and "valve pin" drop out.

You can see where a guy with pliers attacked the stock screw.

My gentler alternative, a spare 1/2" jacobs chuck used as a wrench.

The transfer port seal. Note the metal part of the "Breech Gasket Assembly" or transfer port seal.

I used a dowel to push the valve out the front of the tube.

The valve and cap.

Unscrewing the cap reveals the white plastic (teflon?) check valve and spring.

Now the trigger.

Opens up with two screws. Unlike the better 160 trigger there aren't any adjustments.

Huge trigger & sear unit...

Nothing to it. That's everything except the pump cup/plunger stripped.

Crosman Model 140 Disassembly, Part 1

I picked up a Mongomery Wards branded Crosman 140 in December, pretty cheap. It wouldn't pump up but I figured I had already done a strip of the 140 for the blog, until I checked and realized that while I had rebuilt a horrible 140 in parts and Derrick refinished a 147 stock, we hadn't actually disassembled one for the blog. So here I go.

Dark brown stained stock, plain jane 140.

A nice touch on this 140 was the plastic ramp attached to the utilitarian front sight. I'm not sure if all 140s had this or only the MW ones?

The cap on the breech was chewed up, which is a clue that someone has tried to fix it in the past.

To get the stock off I had to remove the safety and unscrew the lock nut.

I put the safety in the neutral poistion and pushed it out. You can see the plunger tip.

I used my roll pin pusher to remove the pivot pin.

The front sight assembly.

The pump arm and piston slid out. The pump plunger pulled vaccuum on the way out which means that it's ok (borne out by later use) so I won't be removing it. Which is a pity as it requires making a tool to remove the pressed on retainer.

Small dowel pin removed.

Now the breech cover.

Screw removed and cover slid off rearwards.

Rear breech screw.

I used an offset screwdriver to remove the trigger assembly.

Put aside for later.

There's a nylon bushing in the hole that had to be pried out.

You can see that someone tried to pry the cap off the breech but didn't realize the nylon bushing had locked it in.

Using the screw as a lever worked fine.

The cap is really chewed up.

Then the bolt comes out. It looks fine, or at least better than the last one.