Webley Senior Air Pistol - John Walker

Webley Senior Air Pistol - John Walker.

With thanks to David for these pics.

David says:

As far as I know this is the only .177 Senior conversion John did.
I have John's concept drawing for this conversion, as I have for the Mk.2 Service PCP conversion, but by no stretch of the imagination could they be called engineering blueprint drawings.
The main change to the outward appearance of the pistol is the very slightly extended rear plug. This was done to make the insertion and placing of the valve possible. The rest of the pistol looks standard, with the bleed hole at the front and the filler in the butt.
I believe some of these conversions, there were nine in total, are very slightly different in the way the conversion was done, and not all have the bleed hole at the front.
Even though there were only nine Senior conversions in total, the original owner asked for it to be numbered as 10.
It is alleged to give 40 shots at 5.5ft.lbs., although I haven't fired that many shots through it.

[Also] the increased height of the front sight... was done to cater for the increase in power/range over the original power output.

David also says:

The piston is not used. The valve is opened by a brass rod in place of the piston.
Below is an abbreviated concept drawing of John's Senior CO2 conversion.