2240 barely puncturing CO2 canister

[Ironsight]

I've disassembled completely to trouble shoot and reassembled but the problem persists.  The severity is inconsistent in some situations there is barely a hole visible and other times it is half the size as the full plunger diameter.    I received a replacement Crosman hammer spring today as well as hammer pin and a10 inch barrel now installed but did not correct the problem.  Tried adding some washers for preload no change either.  With the tiny puncture, velocity is 235 FPS.    I am open to any suggestions!

Mods include trigger polishing, honing and lighter spring, 0.157" TP and barrel drilled, 10 inch barrel.

[Airnut]

Check your valve poppit the pointed end is what punctures the cartridge.
It could be bent,broken or worn down. Also make sure your hammer is sliding freely and check your valve spring while you're at it. It could be broken.
What brand of c02 cartridges are you using and have you tried a different brand?

[lefteyeshot]

Put a dime at the bottomof the co2 cart.

[Flex]

I've disassembled completely to trouble shoot and reassembled but the problem persists.  The severity is inconsistent in some situations there is barely a hole visible and other times it is half the size as the full plunger diameter.    I received a replacement Crosman hammer spring today as well as hammer pin and a10 inch barrel now installed but did not correct the problem.  Tried adding some washers for preload no change either.  With the tiny puncture, velocity is 235 FPS.    I am open to any suggestions!

Mods include trigger polishing, honing and lighter spring, 0.157" TP and barrel drilled, 10 inch barrel.

To clarify the obvious, the problem seems to the inconsistent degree of the piercing of the CO2 cartridge. Is this a new issue or one that has always occurred? I’m wondering if there’s something that’s preventing the nipple end of the CO2 cartridge from completely seating against the valve assembly? When a cartridge is inserted in the powerlet tube, does the piercing knob completely thread into the tube i.e. no gap? Complete disassembly was mentioned. Did that include disassembly of the valve? Something could be interfering with the forward movement of the valve stem when struck by the hammer 🤔. Airnut’s suggestions are all valid and my money is going to be the first one that points to a valve issue 😎. Good luck and be sure to report back 🙂.

[Ironsight]

* Situation has existed since new, an Amazon purchase back in March this year.  Non returnable!  Also my first CO2!

* When a cartridge is inserted into Powerlet tube, the piercing knob does not completely thread into the tube.  There is always at lease e 1/8" gap.

* Poppit piercing point is blunt with heavy tool marks. 

Have completely disassembled again today:

Valve: dressed and polished poppit piercing point, removed a couple threads for volume, measured stem spring force (1/4 inch @ 2 LBS)

Tube and hammer: deburred and polished

Notes: Hammer/Striker came with a fairly large (oversized) milled groove to accommodate relocated breech screw?  Also tube has an extra drilled and tapped location for potential relocated breach screw?

My thoughts are to cut a link off of the valve poppit spring to reduce piercing energy needed, does anyone else agree?  What else could I be missing?   Maybe a heavier hammer spring instead?
 

[Rick67]

Try cocking it 1st before you put in a cartridge and don’t forget the drop of Pelgun oil or whatever you use.

Cart in, finger-tighten cap until snug.

Pull trigger, then tighten cap again.

Cock for the 2nd time and fire.

Most often the 2nd battery will pierce the cart with gusto.

That C02 cap gap is normal; just put an O-ring around it if it bothers you——I did ‘cuz I don’t like seeing that gap as well.

[Rick67]

Also with an O-ring.

[Rick67]

Also check your sear engagement.

Remove the grip assembly and check if it moves freely as you pull the trigger.

Sometimes the plastic plate is screwed on too tight and would impede the aforesaid.

That tube with the extra threaded hole is for the other type of breech with a different screw location.

Are you using a steel breech?

The reason I'm asking is because during installation the steel breech makes it  prone to binding the hammer pin if you're not careful.

Also check if your hammer falls down freely when at a downward angle; remove the hammer spring for this test.

[JPSAXNC]

The basic design isn't that great, when the gun fires the puncher pin goes forward and blocks the hole. So big hole or little hole they both get blocked. I would look for a different cause of the problem.

[Rick67]

Do you use Pelgun oil or equivalent to lube your cartridge?

[Ironsight]

I use Pelgun oil religiously.

Oh and did install steel breech a while ago did not change the situation any.

Did the hammer tube slide test and all is smooth.

Tried cocking before finger tightening and again after first firing.

Sear moves smooth and freely (trigger pull varies 14 to18 OZ) - over travel screw installed!

I'm curious about the poppit piercing pin spins freely and  seem to have significant slop (wobble).  So basically it is self floating this is normal?
Also considering now drilling valve cap deeper for volume there also reduce spring pre load?   Any recommendations? 

Thanks for all the inputs!

[Flex]

Something is preventing the piercing poppet from making an adequate hole in the nipple of the CO2 cartridge. Too short, bent? The heavy tool marks on the pointy end of the poppet could make one wonder why? Is it possible that the brass collar on the valve stem has slid forward on the piercing poppet keeping it from fully piercing the CO2 cartridge? You might be able to gently tap/push the collar back some toward the hammer strike end of the stem 🤔.  I’m still wondering if the nipple of the CO2 cartridge is seating properly against the front of the valve? With the Amazon return window being closed and the Crosman warranty likely voided by disassembly and some modding, I’d see if a replacement valve stem assembly (part #2250-016) or perhaps even a complete valve assembly (part #2250-003) might still be available from the parts department.

[Gippeto]

Back out the rear breech screw and rear grip screws a bit...may be too long anf binding on the spring.

[Ironsight]

Crosman parts have no valve assemblies or poppits in stock (part #2250-016 or part #2250-003) and do not know when will be available?

Breech screw length interference was checked but will recheck again.

Nipple of the CO2 cartridge is seating properly against the front of the valve.  I cleaned and smoothed the rim for clean entry.

Will attempt next to gently tap/push the collar back some toward the hammer strike end of the stem, see if that might work?

Still contemplating drilling valve cap deeper 0.100" for volume there also reduce spring pre load.   Reluctant because cant get my hands on a backup poppit.

[Rick67]

Back out the rear breech screw and rear grip screws a bit...may be too long anf binding on the spring.

This is pretty common, particularly the top breech screw being to long it hits the hammer spring.

The steel breech requires a 3/4” long screw while the plastic breech a 7/8”..

[lefteyeshot]

Put a dime at the bottomof the co2 cart.

This effectively makes the co2 cart a little longer and might make a better hole in the cart.

[Rick67]

I use Pelgun oil religiously.

Oh and did install steel breech a while ago did not change the situation any.

Did the hammer tube slide test and all is smooth.

Tried cocking before finger tightening and again after first firing.

Sear moves smooth and freely (trigger pull varies 14 to18 OZ) - over travel screw installed!

I'm curious about the poppit piercing pin spins freely and  seem to have significant slop (wobble).  So basically it is self floating this is normal?
Also considering now drilling valve cap deeper for volume there also reduce spring pre load?   Any recommendations? 

Thanks for all the inputs!

That piercing pin movement is normal.

I mean, I’ve never encountered one that is rock solid.

[Ironsight]

Put a dime at the bottomof the co2 cart.

This effectively makes the co2 cart a little longer and might make a better hole in the cart.

With cartridge inserted into Powerlet tube the piercing knob does not completely thread into the tube.  There is always at lease an 1/8" gap so therefore a dime should only increase that gap?

[Airnut]

I use Pelgun oil religiously.

Oh and did install steel breech a while ago did not change the situation any.

Did the hammer tube slide test and all is smooth.

Tried cocking before finger tightening and again after first firing.

Sear moves smooth and freely (trigger pull varies 14 to18 OZ) - over travel screw installed!

I'm curious about the poppit piercing pin spins freely and  seem to have significant slop (wobble).  So basically it is self floating this is normal?
Also considering now drilling valve cap deeper for volume there also reduce spring pre load?   Any recommendations? 

Thanks for all the inputs!

Judging by your picture. I don't see were you have a problem. Yes it could be better but the far left cartridge looks a lot like all of mine. It doesn't take much of a hole to work. The other two cartridges look like the c02 cap was way over tightened.

[Ironsight]

I use Pelgun oil religiously.

Oh and did install steel breech a while ago did not change the situation any.

Did the hammer tube slide test and all is smooth.

Tried cocking before finger tightening and again after first firing.

Sear moves smooth and freely (trigger pull varies 14 to18 OZ) - over travel screw installed!

I'm curious about the poppit piercing pin spins freely and  seem to have significant slop (wobble).  So basically it is self floating this is normal?
Also considering now drilling valve cap deeper for volume there also reduce spring pre load?   Any recommendations? 

Thanks for all the inputs!

Judging by your picture. I don't see were you have a problem. Yes it could be better but the far left cartridge looks a lot like all of mine. It doesn't take much of a hole to work. The other two cartridges look like the c02 cap was way over tightened.

Sorry to hear that! 

Reassembled this evening to gage progress no improvement at all still shooting light (324 to 340 FPS).   Back apart again for another round of troubleshooting.