S510 won't fire

[Nickpan]

the final sear doesnt always move, leaving gun still cocked despite all other sears actioning. An energetic flick of the trigger shocks it into releasing. I have trigger plate off, sear moves ok, I can cock and fire at will, but if I leave it an hour, the big sear sticks. I've given it a quick polish, and put grease on the pin, but what else might cause it to stay? There is a 'bent wire' spring pushing at the back of it, but that seems strong enough. I daren't touch the edge where the sear actually engages the hammer, but that would seem logical to smooth in some way.

[Blackbaronfish]

Whats your location as someone near you may be able to have a look.

BBF

[chris.e]

You might be screwing the side plate back on too tightly.
Don't tighten it down as much and try it.

[poth]

is the sear lever spring in the correct place the last sear needs to be under spring pressure it fits on the post top right as you are looking at the sears with the cover off

[Nickpan]

Hove.
I've just slightly straightened the coiled wire spring, that'll put more pressure on the back of the top sear, I'll leave it an hour, see if it settles and sticks or does what it should.

[Nickpan]

That did it, thanks all