Walther CP-2 Has lost velocity

CW1 · Post by **CW1** » Sat Jan 15, 2011 8:42 pm

My Walther is just lobing the pellets down range This happend all of a sudden one minute it was shooting fine then just lost velocity I am confident it has a full charge of CO 2 I have taken it partially apart and everything seems to be fine just looking at the spring and valve behind the CO2 cylinder

Rover · Post by **Rover** » Sat Jan 15, 2011 9:47 pm

They will sometimes do this if overfilled. They then release only a partial (or no) charge on firing when the cylinder warms.

I hope that's your problem.

CW1 · Post by **CW1** » Sat Jan 15, 2011 10:10 pm

I thought this might be the problem so I bleed some pressure off and it did not help

yana · Post by **yana** » Sun Jan 16, 2011 5:50 am

Sounds like it doesnt take enough 'air'.
When were all seals last changed?
Dont you hear any hissing from somewhere?

CW1 · Post by **CW1** » Sun Jan 16, 2011 8:17 am

No the seals are good it is not leaking there are only 2 seals that are pressurized 1 on the cylinder 1 on the gun.There is a small shaft that connects the striker to the air valve I am wondering if it has gotten to short? of course this would not explain why it suddenly lost power it should have been more gradual

RobinC · Post by **RobinC** » Mon Jan 17, 2011 6:19 am

Just bought and rebuilt one as nostalgia trip, had one new 30 years ago. They are very simple, I think if you had a leak you'd hear it and the cylinder would empty, but recheck the seal, valve base O ring and the cylinder O ring again. Have you changed cylinders and tried the other one? If you think its a weak strike, drop out the trigger unit and then take out the bolt and spring through the back, you'll soon see if the spring or bolt is damaged. Let us know when you find the cause in case it happens to mine!
Good Luck
Robin

Spencer · Post by **Spencer** » Mon Jan 17, 2011 8:49 am

a problem with CO2 guns can be crud on the impulse rod (Ventilstößel) - usually easily fixed by cleaning the rod and its housing with solvent and re-lubricating (VERY lightly).