Quote Originally Posted by andrewM View Post
You were fortunate to solve the problem, I think.

What is a PH16m rear sight? Are you fitting a peep sight where the telescopic sight would otherwise be fitted, ie on the ramp? I did this with a Webley Omega (the peep sight also obtained from Protek) - which has a rather more solid ramp - to great effect. The Mk3 has quite a kick, relatively, so you might get movement on the sight.

A
The PH16 is a Parker-Hale aperture sight that mounts solidly to the rear of the cylinder because the cylinder is drilled and tapped and the sight screws on with two bolts, making it rock-solid, but expensive to fit. So the vast majority of MkIIIs have the standard sights. It was offered by Webley as a factory option.

The aperture can also be swung out of the line of sight, allowing the open rear sight to still be used. The idea being that you could set the open for short range, say rats, and the aperture for long, say, rabbits.