Originally Posted by AndyIoW
Melv would do if he could get an answer from Harry. Just wanted to get other opinions on possible causes.
BTW started on Winter course yesterday, shall we say some pruning is required still
Hi Andy, first make sure that the transfer port is tight but don't put too much pressure and over tighten as the allen key can damage the internal run that the allen key sits into. Could be the transfer port o ring, breech seal but i'm thinking more along the lines of knackered firing valve/valve spring/hammer spring. It's a tricky one to call without getting into the rifle and having a look as it could just be something simple like a very dirty hammer or hammer run in the block. Pity you're not closer as i would have taken a look.
Replacing the reg/reg interface orings are simple enough but i don't see how either of those would could such a huge spread.
o ring 6x2 reg interface and transfer port 3301020026 Qty 2
o ring 24x2 interface to firing valve 6390011 Qty 1
o ring 5,28x1,78 internal loading port/breech 6390050 Qty 1
Servicing and setting the reg can be done for a tenner as long as you have a reg checker.
o ring small regulator 4002090018
o ring large regulator 4002090019
belleville washer 10 3220022
More common problem causes.
Hammer pressure spring FT 4107030002
Hammer pressure spring HP 1200010090
pressure spring firing valve 4101030005
valve complete firing valve 4005020515
My gut feeling would be a full service and reg check as the variation in fps is more than i've ever seen on several hundred Steyr's