Fixing the Crosman 622, Part 2

This is one of those posts where I'm reminded how much I have to learn about working on airguns...

I set up the receiver half with the valve and tube in place.

Carefully aligned, I spotted for one of the cross pin holes with an end mill.

Then I tried to drill through before reaming to 1/8"...disaster! The tube hole started getting oblong as the drill drifted towards the outside of the tube...

I forgot to clamp the piercing assembly in place...if I had just put the piercing guts in and clamped with an empty CO2 cylinder it would have stayed put. But I didn't. At least I caught it before I was all the way through.
This highlights why I buy "beaters", guns that other guys have given up on. If (when) I do screw up I haven't caused some horrible historical loss to the world supply of collectable airguns. Chances are anyone else repairing it would have swapped out a valve assembly that didn't have a big chunk out of it. At least that's what I tell myself as I weep my self to sleep at night.

So now what? Well I do have this hole in the underside of the tube...

I reamed it to 3/16"

Spotted through the valve body to the piercing assembly.

Then removed it and drilled down shy of the gas hole and reamed to 3/16" for a slip fit (not a press fit)

Of course that dowel pin is a little long. It should provide some extra insurance for the tube and piercing assembly.

Ground to fit inside the housing.

Here's how the spring goes on the feed pawl.

Small end against the bushing.

That screw, which I thought wasn't stock, but is, in place.

Finally I returned to the reason for getting into the gun...the spring that actuates the magazine index...that is where the end goes. You cock the gun while carefully keeping all the parts together with your hand then use a screwdriver to bend the long end of the spring under that boss.

Here's another view.

Otherwise it goes together in reverse of disassembly. Use a pin to hold the trigger in place before you put the housing together and screw the trigger pivot screw in (pushing the pin out).

Well it works! I've shot through two CO2 cartridges so far and it held gas for three days in a row.
I'm getting 380-390 fps with 14.3 grain Crosman wadcutters which is about the same energy as the manual's quoted 375 fps w/ 15.5 gr. pellets. It is possibly one of the most fun air rifles I've shot. You can shoulder the rifle and "blam, click clack, blam, click clack, blam..." You get the idea. Maybe I'll work up the nerve to try porting it and using a heavier hammer spring someday for more velocity but as a plinker it's perfect.

Fixing the Crosman 622, Part 1

Well I got started on fixing the problems with the Crosman 622.

The valve with the stripped out mounting holes and Helicoil stuff.

Drilling the mounting holes out.

Just deep enough to kiss the bottom of the hole.

Tapped #10-32 Helicoil (which is larger than #10-32)

The helicoil loaded in the insertion tool.

Inserting...

The helicoil in place.

The original holes are #8-32 I think, but I was able to go to #10-32 no problem except that I had to turn the heads of the button head cap screws down. I used Stainless screws because that was what I had on hand...

In place.

I discovered another small problem, although I doubt it will effect the functioning of the slide.

With the Halves screwed to the valve I noticed there's still a bit of a gap...


Easily pressed closed by hand. I checked and one of the frame halves is tweaked slightly so that it's not flat. There's no good fix for that. It's not a huge deal if I get the whole tube&valve mounted securely.

Checking to see how much room I have to work with for pinning the valve parts together.

I think that this is how I'll pin the valve & tube together although I may make the pins go in horizontally. That way I can assemble the valve & tube connected to one of the receiver halves which should keep everything aligned more or less. I'm taking my time as screwing this up pretty much would wreck the valve body. I'm open to any and all input in the matter...

Crosman 622 Disassembly, Part 2

On I go...
EDIT 11/04/09: I added some more info in the text based on what I've found leafing through the service manual and putting it back together

All of the guts.

The trigger, bushing and spring.

The hammer assembly.

That screw is loctited in and I could see no reason to tempt breaking it off. The hammer looks fine so I'll leave it alone.

The bolt assembly, and valve & tube assembly.

The bolt. This will get more attention as I go into rebuilding the 622...

The spring on the pawl has a large and small end. The small end goes around the plastic pawl.
EDIT 11/04/09: I'm not so sure about that now, seems the large end does...

The bolt is riveted, somewhat, to the pump link.

That screw holding the tube to the valve is not stock.
EDIT 11/04/09: This screw is a stock screw.

Neither is the setscrew on the other side.
EDIT 11/04/09: I still think this one isn't stock.

Both screws removed, and the tube comes off.

The problem with this design of rifle is that a small boss on the receiver holds the tube and the front of the valve against the CO2 pressures. Not good. So likely the previous owner tried to fix it with screws. Which led to a chunk of the valve body breaking...
EDIT 11/04/09: No, it probably broke because it's a bit of bad design on an otherwise great rifle.

The setscrew just bore on the inlet valve assembly. Not good either, really.

Standard 38 piercing pin and seal.

At least I have a bunch of those laying around, although this one looks fine.

The exhaust valve, spring and inlet valve assy.

Another view.
Well she's all taken apart, now I have to figure out how to pin the valve to the tube (Mac1 Airguns will do this for you, if I was less foolish I'd probably send this to him) so that everything is retained stress free. That'll take a bit of thinking.

Crosman 622 Disassembly, Part 1

I picked up this Crosman 622 with a "WTB beaters" ad on the yellow forum (I need to run another one of those...) It had a jammed clip (easy to get it unstuck) but seemed to need a complete overhaul...I couldn't get the clip to index and "in for a penny" as they say.

The rifle with the butt stock removed.

The rear sight removed.

Setscrew holds the barrel to the receiver.

Loosening the barrel band.

Barrel slips out.

Two screws hold the forestock on.

Removed. Those two bushings ride on the tube.

They have a plastic insert.

Unscrewing the receiver LH screw...

Pretty stripped...not good. So project #1 will be helicoils in the receiver screw holes (holes...keep reading.)

This little plastic thing is used for unsticking the clip, used only on later models.

Where it goes.

And the back side...

The trigger group.

Safety removed.

Safety and stock nut.

That spring has a detent plunger at the other end.

Pretty caked with grease.

The other side of the receiver. That screw isn't stock...

Definitely not stock. And slightly too long, causing the valve assembly not to sit flat against the receiver and not allowing the two pieces to close...
The things you find in used airguns.