Quote Originally Posted by Neil54 View Post
Must be touching or the stock screw pulling something out of line.
Just a thought, is the stock screw too long.
Try stock on with no screws.
Yes thanks for the response, the stock screw is standard nothing is customized as far as the stock and bolts are concerned, so it's a bit strange. I'll look again today, from memory of yesterday with the screw out of the stock, it pumps OK. A thought on this is whether the trigger plate that holds the pin from firing isnt engaging properly, can this plate be adjusted or moved to stop slippage. Looking at it, it isnt worn but not sure it aligns fully to block the pin from slipping before the trigger is pulled. The reason I bring it up, is when I replaced the valve to barrel port seal, I've used a couple of different thicknesses, and I've noted that a thicker type allows for the firing pin to slip past the trigger plate.

So I'm wondering if tightening the stock down and the pump cylinder / trigger assembly may be allowing the valve pin to slip past the trigger plate.

Dunno, just a gut feeling really and it seems to have occurred when I tighten things up.

I'll look again tonight after work and I'll try your ideas and exhaust the possibilities. But does anyone know if the trigger plate can be moved/adjusted to stop the pin passing so easily.

Atb