Rob, the front sight is made using a Parker Hale silencer. The barrel band of a QB78 is a perfect fit on it to make a sight protector. I tighten the silencer on and mark the vertical position for the blade. Then drill and tap the silencer to fit a locking screw so everything stays put on the rifle, and the rifle is not changed in any way. Here is a pic taken before I shaped the front blade.
I use little Belleville washers from BSA regulators to make aperture sights and glue them on. Here is a repaired Jackal sight before cleaning up.

Baz

[IMG][/IMG]
[IMG][/IMG]