anyone tried the lothar walther barrel on a crosman co2 pistol?

[Andrewjames]

While balancing the hammer and valve springs does get some results, it only gets you so far.
The absolute best thing you could do IMO, is make a Stopped Spring Guide. If you are a bit handy and have some basic tools they are not hard to make.

I made one for my .177 2240 target pistol a couple of years ago, and it gets me 120 shots at 3.5 ft/lb, with a good band of consistency.

See this thread: http://www.airgunbbs.com/showthread....40#post7231940

If you have any questions just ask away.

I will be making this my next project! i expect i will have questions, stay tuned for the weekend

Andy

[eyebull]

I will be making this my next project! i expect i will have questions, stay tuned for the weekend

Andy

Forgive the crude drawing, but this is basically what I built:

[Andrewjames]

Forgive the crude drawing, but this is basically what I built:

Looks great, i will have a go.. question, how would you adjust the power on that system? should the power be adjustable? i guess you can with a co2 power plant?

best
A

[eyebull]

Looks great, i will have a go.. question, how would you adjust the power on that system? should the power be adjustable? i guess you can with a co2 power plant?

best
A

The trouble with external power adjustment on a 2240 is that if you've done a few other mods it's not difficult to crank the power right up past the limit. For the pistols at least it's best to set the power internally (leaving a decent margin for the coming summer heat) and be done with it.
While the 2250 rifle is a PITA to get to full power, the 2240 pistol has the opposite problem.

With this system you set the power by adjusting the length of the allen bolt (I had a few on hand so was able to play around chopping them up), by using different springs, and by adjusting their preload with the two nuts. Once you have it where you want it you can loctite the nuts and then turning the allen bolt from the outside will not effect the power. The amount of preload on the spring, and the clear distance between the spring and hammer, is what changes both the power and the amount of hammer bounce.
You'll know when you are getting there because the report on firing will sound quick and sharp, rather than 'farty'. If you have a moderator on it will be just as noticeable if not more so.
This does meaning a few repeated teardowns/builds, but taking the time to get it right is rewarding.

[TonyL]

The trouble with external power adjustment on a 2240 is that if you've done a few other mods it's not difficult to crank the power right up past the limit. For the pistols at least it's best to set the power internally (leaving a decent margin for the coming summer heat) and be done with it.
While the 2250 rifle is a PITA to get to full power, the 2240 pistol has the opposite problem.

With this system you set the power by adjusting the length of the allen bolt (I had a few on hand so was able to play around chopping them up), by using different springs, and by adjusting their preload with the two nuts. Once you have it where you want it you can loctite the nuts and then turning the allen bolt from the outside will not effect the power. The amount of preload on the spring, and the clear distance between the spring and hammer, is what changes both the power and the amount of hammer bounce.
You'll know when you are getting there because the report on firing will sound quick and sharp, rather than 'farty'. If you have a moderator on it will be just as noticeable if not more so.
This does meaning a few repeated teardowns/builds, but taking the time to get it right is rewarding.

Have you also played with fitting top hats and rear guides for the hammer spring?

It's something I've often thought of and maybe improve the refinement? Can't remember if I've seen references on the 'net or if people like G-Mac already offer them? So, once a spring and preload value has been arrived at, make those items to give the correct preload.

Have you also tried polishing the hammer and the tube? Again, it's something that I haven't got round to, but may also help?

[eyebull]

Have you also played with fitting top hats and rear guides for the hammer spring?

It's something I've often thought of and maybe improve the refinement? Can't remember if I've seen references on the 'net or if people like G-Mac already offer them? So, once a spring and preload value has been arrived at, make those items to give the correct preload.

Have you also tried polishing the hammer and the tube? Again, it's something that I haven't got round to, but may also help?

You can put a top hat and guide on the hammer spring - .22 short cases are good for this - as well as polish the hammer and tube, and it does make it smoother to cock, but it doesn't really address the issue of hammer bounce. That's not to say that a certain amount of balancing the valve and hammer springs won't reduce it somewhat, but it is made more difficult by the fact that you always need a certain amount of force against the valve spring in order to pierce the CO2 cartridge with the initial shot (unless you are bulk filling, but then if you are using a buddy bottle you have even more to gain from the SSG).
The point of the SSG is to give negative preload, if you like, so that when at rest and uncocked the hammer spring is not in contract with the hammer at all, and the hammer spring is under preload. This means that when the hammer comes bouncing back off the valve pin after firing, it can't pick up enough energy from the hammer spring to knock the valve open again. It's difficult to get the same effect when the hammer is in contact with springs at both ends.

[TonyL]

Good info, Eyebull.