I never leave mine fully charged, I just leave at 100bar, my reasoning is that less pressure on the firing valve, might make it last longer, seems to work for me. Rog

Loads of YouTube stuff on the S-Series they are all pretty much the same Rifle, only differences really are bolt or side lever, or in your case also the barrel, same triggers internally also. Any probs just ask. Rog

To be honest , the S series are pretty much all the same If you want to look at schematics, airarms S500 hft schematics, look under discontinued rifles. The FAC version is not for you, different pot and maybe a couple of other bits. Does your rifle have antitamper fitted ? And what year is it ?. And...

Very easy to fit, good instructions, and they don't have or need a safety

I wouldn't worry about it, just the hammer spring, quite a few do it

Where abouts are you based ?
A/A will do it, but it won't be cheap
Julian on here is probably your best bet

S427 is the transfer port seal,
My S410 .22 is running at 565fps 11.36ftlb with AADF5.52 16gn
That's at about 130bar, well enough

Silicon grease might not be a good idea on metal to metal contact, I wouldn't use it myself

Leave the hole in the pot alone
And what pressure are you filling to when you chrono it ?

Ok, what did you set the firing valve at ?
Have you inadvertently blocked the transfer port when refitting the seal ?