Lighter Hammer Spring for 2240? - More shots per CO2

[saxpride]

Just got a 2240, tired of pumping my Daisy and just want to shoot more

This is my 2nd crosman...my first was a P31 that was recalled by Crosman so I had a bunch of CO2 canisters laying around.

I want to get more than 35-40 shots per canister, and I'm not interested in getting a power adjuster. 50+ and I'd be happy, 100+ and I'd be ecstatic! Looking to save money and not spend a gajillion dollars on mods.....

Is it possible to just compress the hammer spring a bit (over squeezing it a controlled amount) and test for shot count improvement?

Otherwise, are there any vendors that have a lighter weight hammer spring?

Any other ideas to increase CO2 efficiency, as in more shots per CO2 canister? I'm trying to get the 2240 .22 to shoot well under $0.03 per shot, I'm at $0.018 per pellet (Crosman Premiers) and I get CO2 canisters for about $0.50 each. Not interested in going to .177 yet either!

Thanks for any suggestions!

slug9

[daveb50]

I put a pressure adjuster assembly and valve spacer for the 2300s in mine, getting about 60 shots per cart now.
Part #2300-124 Pressure Adjust Assy. and #2300-037 for the Spacer.
https://support.crosman.com/hc/en-us/articles/203544730-2300S-Owner-s-Manual-EVP-2007-Present-

[BigTinBoat]

Just cut the hammer spring 1/2 coil at a time.

Here is a post where I tested mine

http://www.gatewaytoairguns.org/GTA/index.php?topic=71531.0;nowap

I did mine based on an older post I found by one of our resident HPA/Co2 experts

http://www.gatewaytoairguns.org/GTA/index.php?topic=27198

[rsterne]

Yup, cut the spring 1/2 coil at a time....

Bob

[saxpride]

Thanks guys,

The Hammer Spring mod sounds like the ticket. I'll order an extra OEM Hammer Spring....just in case I screw things up. These posts you guys made....are AWESOME. Makes understanding the principles behind the mods much easier to understand. Looks like a large gain in efficiency, with small losses of velocity.

Thanks BigTinBoat for noting how much of the coil you cut, gives me a guideline.

I had no idea about the valve spacer, so that looks like a good option in the future too! Thanks daveb50!

Has anybody tried an Hammer Debouncer Device (HDD) before? Link to someone's results: http://www.crosman-air-pistol-owners-forum.com/board/index.php/topic,2579.0.html

The HDD looks like it frees up CO2 efficiency without sacrificing power, which is a big plus. But I'm thinking with the shortened hammer spring, that too reduces wasted CO2. The effects of the HDD will be minimal with a shorter hammer spring.

I wonder if the HDD requires a steel breech, or if it'll work with the plastic breech.

[BigTinBoat]

Thanks guys,

The Hammer Spring mod sounds like the ticket. I'll order an extra OEM Hammer Spring....just in case I screw things up. These posts you guys made....are AWESOME. Makes understanding the principles behind the mods much easier to understand. Looks like a large gain in efficiency, with small losses of velocity.

Thanks BigTinBoat for noting how much of the coil you cut, gives me a guideline.

I had no idea about the valve spacer, so that looks like a good option in the future too! Thanks daveb50!

Has anybody tried an Hammer Debouncer Device (HDD) before? Link to someone's results: http://www.crosman-air-pistol-owners-forum.com/board/index.php/topic,2579.0.html

The HDD looks like it frees up CO2 efficiency without sacrificing power, which is a big plus. But I'm thinking with the shortened hammer spring, that too reduces wasted CO2. The effects of the HDD will be minimal with a shorter hammer spring.

I wonder if the HDD requires a steel breech, or if it'll work with the plastic breech.

Never tried an HDD, why? Personally I think it's a gimmick.

I have the valve spacer in my 2300T. I have not taken that gun apart as stock it gets over 100 shots.

[rsterne]

Some info here....  http://www.gatewaytoairguns.org/GTA/index.php?topic=59537.

Bob

[daveb50]

I bought a HDD from AOA for my 2240, it broke with very little use, and they wouldn't replace it. It was a small piece of slotted plastic tube, what a waste of $20.

[Powder burner]

Just get a lighter spring like in the 2300S. 

[Ribbonstone]

Just some ideas that have worked out for me.


Just reducing the striker spring would do a good job of increasing co2 shot count.  Basically have a constant pressure of gas, so making the valve softer just opens the valve less, and both shoots slower and uses less gas.

Can get into the weird situation that a warm gun shoots slower than a cool one, but at a constant pace of shooting and a more-or-less constant temperature, just reducing the striker spring does a good job.

(Cool gun has less co2 pressure, so the weak striker hit actually opens the valve farther and can end up shooting faster.)

Way down in speed, may find that the full weight striker moves kind of sluggish…which often translates into inconsistent speeds.  Just seems that the slower the striker is moving, the more prone it is to fictional changes.

So to get even more shots (at low speeds) can go to a lighter weight striker.  Lots of ways of reducing striker weight, from nicely done lathe-jobs to crude bench-grinder jobs.   Really light ones can be made from materials other than steel.


Stock striker:



“Belted” weight reduction (lathe):



“Flat” weight reduction (grinder):



Can reduce the transfer port size so that only a little bit of gas can pass into the barrel at each shot. 

This is a transfer port from a challenger…that’s how that rifle manages to strangle down the speed to about 5 foot pounds.



Top valve has the tiny port in a Crosman 2000 Co2 rifle (a 12gr. rifle that was low speed/lot of shots):



Last trick is to limit the internal valve volume.  Basically, if there is less co2 in the valve, then less can be released at the shot.


Crosman used that trick on a 2300S.  Nothing more than a brass ring that slips inside the valve halves.  Which does two things: (1) Slightly reduces the volume of gas inside the valve and (2) reduces the gas passage around the valve stem by the thickness of the spacer.


Rough estimate of the one found inside the 2300S valve:



Spacer in place. Hard to see, but can notice the more limited space between the valve stem and the valve wall:



BTW: go low enough in striker force, and you’ll have a harder time getting a 12gr. to pop open.  Lower force to the valve stem is also low force to the piercing stem.

That can be a mixed blessing.  If the hole is truly tiny, then it is LESS likely to inject liquid co2 into the valve.  Have had the hit so weak, and the hole so small, you could actually hear a little  ¼-½ second internal “hiss” as the co2 moved from the 12gr. into the valve.

Result of all of this is that if you can live with really low speeds and take the ideas above into consideration, can manage 90-100 shots (low speed, but accurate) per 12gr.