Neil works his magic on a modern classic PCP
In part two - Neil concludes his trigger restoration on a classic Air Arms S510 rifle.
19 This is the contact surface where the middle sear contacts the hammer sear.
That surface should slide a bit smoother now.
When putting the sears back on to their pivot pins I put just a smear of gun oil on the pins.
When removing the hammer sear, it fouls on the aperture in the action and cannot be removed as it is.
With a suitably-sized pin punch and a small hammer, the hammer sear pivot pin can be knocked part way through the trigger housing.
Only knock it through far enough to allow the top hammer sear to be removed.
The contact surface on the hammer sear before being polished. 26 How the contact surface looks after polishing.
The top hammer sear positioned back over the part of the lubricated pivot pin that is still protruding through the trigger housing. The top sear return spring is held down out of the way of the top sear with a small screwdriver until the sear is fully seated, and then the spring is released into its correct position.
The hammer sear pivot pin can then be knocked back flush with the back of the trigger housing.
With the tip of a small screwdriver, I now put a smear of Moly grease on all of the contact and bearing points.
The owner of the rifle had picked up a replacement brass trigger from Rowan Engineering and asked me to fit it:
Rowan Engineering Ltd. Unit 9, Overfield Thorpe Way, Banbury Oxon OX16 4XR
The replacement Rowan trigger just slips over the original pivot pin. The middle sear tension spring and grub-screw can now be replaced. I put just enough pressure on this spring so that the trigger when cocked has just a slight pressure on the first stage.
With the 1.5 mm A.F. hexagon drive key supplied with the trigger, I adjusted the front screw to give around 3mm first travel on the trigger.
The rear screw sets the let-off point of the trigger.
The later S400 and S500 models have a spring that locates between the trigger housing and a protruding lug on the trigger. This is to give a positive ‘feel’