.22L.R. revolver hammer spring question

[5-SHOTS]

Hi experts of THR, I have a Weihrauch HW9 Target Trophy revolver that is not reliable enought for my tastes when shooting double action (no problems when shooting single action).
I'm thinking a slightly overpowered hammer spring can cure the problem but I can't find anything listed for my revolver. I'm sure Wolff could have something but I don't really know which pack or kit (general purpose or even made for another handgun) to get.
Here is the dimentions of the spring I have:
esternal diameter: 4.9mm (about 1/5'');
internal diameter: 3.3mm (about 1/8'');
diameter of the wire: 0.8mm (about 1/30'');
lenght: 48mm (about 1'' 7/8);
number of coils: 26.
I'm thinking that a longer spring with one or two coils more can solve the issue.
Is there anything similar on the market?

Best regards, 5-SHOTS.

 

[RaceM]

You could try shimming the bottom of the mainspring first to see if that's really your problem. Could just be it doesn't like whatever ammo you are using in double action.

 

[5-SHOTS]

Thanks RaceM, I've already tried to shim the spring without much luck. The problem is also that adding just only a 1/14'' shim makes nearly impossible to riassemble everything. I'm guessing that one more coil, which adds only 1/30'' when the spring is compressed, is the way to go.
Yes, it's true that my revolver doesn't like DA shooting (I think it is designed basically for a SAO shooting, so the problem it could be ME). The only ammo which is 100% shooting DA is Fiocchi 40gr. MAXAC.
I've e-mailed Hermann Wheirauch Revolver GmbH and they asked me my address, hopefully to sent me a different spring.
If I can't solve the problem I'll keep the Weihrauch as it is and I'll shoot it SAO. And I'll get a Ruger LCR22 to practice DAO.

Other news about aftermarket springs will be appreciated.

Best regards, 5-SHOTS.

 

[LAGS]

Check your double action timing.
If the cylinder is still rotating when the hammer falls, you may not be getting Full impact of your firing pin on your casing.
I have that issue on a lot of the old revolvers that I try to get working again.
They fire OK in single action, because the chamber is already rotated Up to the correct position.
But in double action the cylinder is still rotating as the hammer falls, causing a Glancing Blow on the primer.
You can sometimes see the differance in the casings by looking at the firing pin dents in the case rim.

 

[5-SHOTS]

Check your double action timing.
If the cylinder is still rotating when the hammer falls, you may not be getting Full impact of your firing pin on your casing.
I have that issue on a lot of the old revolvers that I try to get working again.
They fire OK in single action, because the chamber is already rotated Up to the correct position.
But in double action the cylinder is still rotating as the hammer falls, causing a Glancing Blow on the primer.
You can sometimes see the differance in the casings by looking at the firing pin dents in the case rim.

Hi LAGS, the timing is perfect both single and double action with the cilynder that stops before the hammer falls, just like a good S&W. Today I have spoken with a gunsmith and he told me that the spring is in good shape and the problem is that in double action the hammer is released when the spring is not fully compressed. That's not surprised me because a shorter DA than SA stroke sounds normal to me with all revolvers (however, I could be wrong on that).
IMHO at the Weihrauch factory they putted a soft spring to have a good, light SA trigger and sacrificing something in the DA reliability department. Infact, having heard and red all the horror stories about how hard is a DA pull on rimfire revolvers, I can't say the same about mine.
I'm still guessing that a stronger or a slightly longer spring is the way to go.
In the mourning I've tried to find something at my local hardware shops whithout any luck.
I hope Weihrauch send me a new spring.

 

[5-SHOTS]

Update

Yesterday mourning I've received a new spring and a new swivel from the Weihrauch factory and installed them. I've tested the gun at the range in the afternoon with some ammunition that were problematic before the fix: no more misfires when shooting DA. For some reason the trigger is even better than it was before. I've carefully checked the hammer travel and it is actually way shorter when shooting DA than SA: a design choice I guess, because everything works perfectly.
I'm an happy Weihrauch customer .
Best regards, 5-SHOTS.