Help!

[Micky Spillane]

Oh wow that is one blinged up gun! I wound up doing a complete strip down and removed the Co2 cart still attached to the valve ! I then had to put the Co2 cart into the vice and knock the valve off with a spanner/mallet combination not nice. On reassembly I found the transfer port seal loose in the gas chamber and fitted it correctly this may be the poor performance cause as it has been poor from new so I believe the quality control at assembly was at fault. Tired now but will run a string tomorrow and see what that brings.
Thanks very much for your input, drilling the side of the air chamber seems like an idea if this becomes a persistent problem.
Many thanks for your help.
Mick

[Micky Spillane]

Well sadly non of the above wrked, this pistol is still only producing half of the advertised power. Unfortunately, a) I have lost the receipt from Greenfields who in all fairness offered me a replacement gun and b) I have been fiddling with it so have probably voided my warranty. £110 for a pistol that didn't match up to the advertised specification plus the expense of all the add ons that I purchased in good faith saying that they would produce the required result. Not bank breaking disasters but my trust in some things (like GMAC Customs and Crosmans) is a thing lost for ever.

[Tony.T]

Ref low power look at getting a modified firing valve from TR Robb. I got one for mine and had to turn the power down!

If a capsule sticks, remove the cylinder end cap and 'cock' and fire the pistol usually does the trick!

[AC all day]

As above.....if a capsule sticks I just recock the gun and fire and out pops the capsule.....
Crosmans can be a little low on power and not as advertised, but there are so many ways to tinker and play with these.....5.5 ft-lb is well achievable in the pistols and still a good shot count. I have longer pellet probs.....stronger hammer springs, you can have ported transfer ports too, but that put me the wrong side so got removed, I might try again with weaker hammer springs...

[Benelli B76]

Cocking and firing to loosen the capsule doe not work in a lot of cases I have fixed. The piercing pin is just punching into an already existing hole in the capsule. Some I have weighted the capsule with heavy magnets and fired at the same time and still remains in place. What I do in most fixes is open the brass seal recess slightly and fit a harder polyurethane capsule seal.

Baz

[Micky Spillane]

Ref low power look at getting a modified firing valve from TR Robb. I got one for mine and had to turn the power down!

If a capsule sticks, remove the cylinder end cap and 'cock' and fire the pistol usually does the trick!

Harrumph! TR Robb doesn't seem to do them anymore. Not on the website anyway.
Thanks for taking an interest though.

[Paul55]

Well sadly non of the above wrked, this pistol is still only producing half of the advertised power. Unfortunately, a) I have lost the receipt from Greenfields who in all fairness offered me a replacement gun and b) I have been fiddling with it so have probably voided my warranty. £110 for a pistol that didn't match up to the advertised specification plus the expense of all the add ons that I purchased in good faith saying that they would produce the required result. Not bank breaking disasters but my trust in some things (like GMAC Customs and Crosmans) is a thing lost for ever.

It's a bit unfair to rubbish GMAC over what sounds like a faulty valve in your gun. How many shots did you get from the Co2 that got stuck? I've never had a Co2 cap get stuck to the extent yours was & I've built a fair number of them.

https://imgur.com/a/tNLdpgr