Pro sport f*+% up help

[Anchorman]

Sorry but I cannot understand why the thickness of the flange on the spring guide is so critical when you can add up to 3 preload washers between the flange and the base of the spring effectively making the flange much thicker
Dave

[cooper_dan]

Sorry but I cannot understand why the thickness of the flange on the spring guide is so critical when you can add up to 3 preload washers between the flange and the base of the spring effectively making the flange much thicker
Dave

The flange is the full inner diameter of the action (i.e as big as the OD of the piston). When you cock the rifle, the piston will come back and stop against the flange

The pre-load washers are smaller diameter and fit inside the piston. So when the rifle is cocked the piston slides over the washers.

[Phil Russell]

Sorry but I cannot understand why the thickness of the flange on the spring guide is so critical when you can add up to 3 preload washers between the flange and the base of the spring effectively making the flange much thicker
Dave

If you add washers on the guide between the guide flange and the end of the spring you are, in effect, adding length to the spring provided that the washers are the same diameter as the spring and do not impede the movement of the piston up against the flange. If the flange is too thick then the piston body cannot bring the piston rod far enough into the trigger mechanism to adequately set the trigger and / or safety catch. Next time you have your PS apart, offer up the piston and spring guide assembly, minus spring, to the trigger block and you will see what I mean. The necessary clearance is very small and I believe the need to 'yank' on the lever is due to the clearance being just too fine to allow adequate movement every time the rifle is cocked.
The same effect is seen with a 'just coilbound' system or where the spring guide body can just touch the end of the top hat during cocking.
Hopefully I am correct in all this. I determined my 2.8mm by trial and error some time ago ... but it worked.
Cheers, Phil

[Phil Russell]

The flange is the full inner diameter of the action (i.e as big as the OD of the piston). When you cock the rifle, the piston will come back and stop against the flange

The pre-load washers are smaller diameter and fit inside the piston. So when the rifle is cocked the piston slides over the washers.

Ah, beat me to it and a far more understandable answer.
Watching it in action off the rifle helps ...
Cheers, Phil

[Anchorman]

Ah, beat me to it and a far more understandable answer.
Watching it in action off the rifle helps ...
Cheers, Phil

Thanks. Understood now

[Daveo]

Finally sorted it!
I was sick of stripping it down so I decided to leave it a few days.
Flange on the guide turned down to 2.6mm with one 5 MM preload spacer and the guns shooting nice.
The safety engages most of the time but oddly the gun will fire without having to recock it.
The only thing I can think would be to take a mil off the back of the piston?
Also discovered the stud that holds the rear stock bolt was protruding too far into the trigger housing and fouling the piston rod, which was the click I could hear on cocking
I've put a few pellets though the gun and its grouping well and it feels "easy" to shoot
Certainly no felt twang like there was.
I'll put a few pellets through then test the power
which will be interesting because the gun is running a short stroke piston and a HW piston seal
I'm not sure what affect that will have.
Thanks for the help sorting the gun gents