My enfield n 4 T scope

[Peter Laidler]

Wind the range drum from 0 to 10 and make sure that the central reverse headed part (this is the lead screw that controls the up and down movement of the graticle) also rotates with the drum. The lead screw MUST be firmly locked to the drum.
NOW do the same 0 to 10 again several times but look through the telescope and see that the tip of the graticle moves up and down as you rotate the drum. And that it always comes to rest at the same visual point at each end of the range scale.

Repeat this with the deflection drum.

It would appear that the range lead screw is not locked to the drum and the same to a slightly lesser degree with the deflection drum. You can positively lock the lead screw to the drum via the leas screw locking nut. But do not wrench it down like you are tightening a lorry wheel nuts. It's just got to lock the screw down