View Full Version : Disassembly of a cad scope

05-06-2011, 07:26 AM
I recently bought a LOVELY genuine cad scope from Greg for my late HT rebuild - all original, just missing the scope and rings.

I have ordered a set of rings from Robert Speilauer, who is making them rough mill like the late ones were. Now comes fitting them...

I would really appreciate any advice, tips, or walk-throughs on scope disassembly so I can have the rings soldered in place. I have found a custom gunsmith here who has done it before and will do it for me, but he too wants disassembly advice of course.

To remove the rear bell, do I first need to unscrew the small screw on the underside, and then turn the rear bell housing off by hand? OR do I need to remove the rear occular alloy ring as well? And how does the turret housing unscrew so I can mount the front ring? Do I need to remove the turret dial 3 screws first to remove the dial and the turret base screws are under? Or?

ANY advice, tips etc SINCERELY appreciated!

05-06-2011, 02:45 PM
Hi Vulch

I have a cad scope here disassembled here (without rings) for restoration.

The ocular bell should just unscrew from scope tube, if tight put on the industrial rubber gloves to gain some purchase to unscrew. You only need to remove eye retaining ring to remove ocular lenses and spacer if need cleaning. The screw at 6 O'Clock you refer to going through tube is the erector cell retaining screw, non adjustable as Kahles factory set for a person with 20/20 vision, however can be adjusted but means trial fitting and tapping a new threaded hole in erector cell body. Once ocular bell removed you should see a Zamak alloy baffle in end of tube, this can be tight to remove, be careful the old Zamak can be brittle and or corroded and shatter. Warm tube area if necessary with hair dryer to help expand tube and remove.

Range saddle just remove 3 range dial disc retaining screws, remove disc and 1-8 marked dial then unscrew lead screw retaining screw. Remove knurled range dial knob this will expose top of lead screw and range saddle screw. Remove range saddle screws and pull off saddle this will leave lead screw still in reticle carrier, unscrew lead screw from carrier. I presume you have sussed out how to easily remove OG lens/sunshade assembly?

Now for the fun parts. If you can reach in with finger and try and pull out erector cell assembly towards ocular end of tube (keep rubber glove on and use one finger for grip). The trouble is the Zamak Alloy parts after all these years can swell up in tube and bind tight as well as rust forming in tube interior. If erector cell wont budge you are going to have to press out erector cell into reticle carrier and push it all out of OG end of tube, watch reticle diaphragm is not damaged as exists tube, trick is to exist it enough to be able to grip it and remove by hand. You may also need heat to expand tube but not so much that you melt erector cell lens balsam, if necessary use a penetrating oil or WD40 but bank on having to clean parts and clean erector cell lens afterwards. You may need to use a press to remove these parts and they can and have come out in shattered pieces in scopes before now due to brittleness of the Zamak Alloy.

Hope this is of help, if needs be I may be able to take some pictures over weekend.

Might I suggest that as Robert Spielauer is well aware of the problems with cad scopes and dismantling/restoring that you fit his rings to rifle bases, then slide in a turned down 27 mm bit of tubing and temporarily fix them and send back to him with scope so he knows exact ring spacing and let him solder whole assembly? I realise though that cost of this may be a prohibitive solution. However if parts break during disassembly he has the machinery to replicate.

05-06-2011, 03:44 PM

I'd really appreciate an explanation on how to remove the Objective easily, as well as how to get to the reticle etc. The cad I have is in SUPERB condition, but of course don't know the internal condition just yet.

If I get "scared" enough, I will assemble and do as you suggest sending to Robert or to Vaughn (whoever comes in cheaper :) )

Thanks again - and will REALLY appreciate the pictures!