Webley Mk3 issues

[andrewM]

I have found Superdomes and H&N Sniperlight to perform well in mine.

The link from Deejayuu was most interesting. Within that link was a further link which is worth reading in terms of the posts therein:

http://www.airgunbbs.com/showthread....r-loading-taps

I also noticed these posts:


Prof51mtw
Good Morning Mick: Yes, the compression ratio or, more specifically, the peak cylinder pressure will have an effect on the optimum TP size. Whether lubricant vapour combustion is present also has an effect, as Jim has just pointed out to me, citing the fact that Weihrauch reduced the size of the TP on the HW55 when moving over to plastic piston seals.
Mike

T20 Super Moderator

Thank God for that --- I thought I'd been imagining it.

As Jim has pointed out Weihrauch changed from a 4mm transfer port to a 2.8mm port when they went from leather to synthetic seals --- so in effect they doubled the static compression ratio.

I'm finding leather seals like to work at a sub 200:1 compression ratio and synthetic seals and O rings work best at 300 : 1 upwards.

The Webley MK3 has one of the lowest compression ratios I have found at 80:1, I am considering fitting a Diana 52 piston seal to one of mine and then sleeving the transfer port down to 2.5mm --- on paper this should make it a bit more user friendly.

Unquote.

This is really into the technical detail but also sheds further helpful light on the subject.

A