Why is the takedown feature blocked on so many Rigby and other British rifles, like on my G.Gibbs Mannlicher-Schoenauer? The answer may be found on page 5 of the 1924 Rigby catalog, quote:
"The "Take Down" Model.
In this Model the barrel is removable so that the rifle may be carried in a short case. We do not recommend this if our telescope sight is required."