Hammerli AP20 - low velocity problem

[PhilipM]

The Hammerli AP20 of my shooting friend developed a low velocity problem : pellets now make an oval shape in the paper target and using a chrony the speed was only 100 m/s. Another AP20 in our club produces a velocity of 150 m/s and shoots nice round holes.
The manual of the AP20 is silent on adjusting velocity and after having removed the grip there seems nowhere a screw for adjusting velocity. I own a Steyr pistol and adjusting velocity is fairly straightforward.
Does anyone know how to adjust the velocity of a Hammerlie AP20 or do we need to ship it back to the dealer for maintenance ?

[TenMetrePeter]

check out the exploded diagram at
http://www.bisley-uk.com/products.php?c=556
The striker bar part 47 and spring 78 doesnt seem to have an adjustment.
Has any silicone oil got inside onto the striker bar ? That can kill a striker weight.

[PhilipM]

Has any silicone oil got inside onto the striker bar ? That can kill a striker weight.

The AP20 has not been disassembled or oiled but we'll try to check for this. Thanks for the suggestion.

[ltiller]

Has any silicone oil got inside onto the striker bar ? That can kill a striker weight.

The AP20 has not been disassembled or oiled but we'll try to check for this. Thanks for the suggestion.

I pick mine up last week and filled my Feinwerkbau first and then the Hammerli not realizing that it takes air only. About 140 shots fired and then it stopped, any ideas how to get it up and going again?

[hundert]

what did you fill it with? Oo