Yes this is a Mk 2 variant from Numrich. I certainly didn't overtighten the lock rings and just followed the instructions in your book. The were left finger tight initially. I had a collimator fitted at the time and noted the settings for future reference. I tightened the rings just a bit to make sure everything was secure and checked the collimator to see if the reticle had shifted which it had and thats when I discovered the problem when I tried to adjust the elevation. there was
Quote Originally Posted by Peter Laidlericon View Post
I have never had one of these things apart but I knew that Warren on this forum has had dealings so maybe he'll come in here.

BUT, if you have no range adjustment, it seems to me as if the lead screw nut part of the diaphragm assembly has unscrewed from the leadscrew.
As for the drums locking up when you clamp-up the lock rings (can I assume that you mean the lead screw locking rings as it's a Mk2 variant?), well, I might sound a bit glib here, but my advice has always been - well don't do the buggers up tight then! If you are well forwards on the advance into Antwerp in 1944, then tight is fair enough but if you are shooting at targets for fun on a well manicured range on Salisbury Plain in 2012, then your lead screw clamping nuts only have to be tight enough to lock the lead screw. Nothing more nor less. I have seen them tightened down like Jumbo jet wheel nuts