can anyone explain how the adjustments work on a voigtlander scopar b scope vintage 1908 has a dial on top marked 100,200,300yds.with a stem pointing to rear and scpe tube plus 1-3 and minus 1-3 scope is numbered to rifle would like to have a idea on how to opperate controls without just turning stuff looks like a sniper scope usesd on ww2 rifles i have seen thank you

Not sure I've seen that scope, 2barrel, but googling your words for it brings up a conventional-looking early 20th-Century German model.

I couldn't see the range markings you mentioned, though your reference reminds me of Kahles's second model, the 1904 Telorar, said to be the world's first scope with ballistic-drop compensation. That one had the ranges you mentioned on a sleeve circling the middle of the main tube, near the first focal plane.

It probably moved the reticle with an eccentric but I would see a dial on top as more useful.

So, how does it work? The 'stem' sounds like the screw lock common before good friction and click systems. If you undo it the dial should turn (unless the mechanism has seized-up from disuse).

A skilled gunsmith would probably have hand fitted the mounting to be at least boresighted to shoot near zero at 100 metres and, unless the 'plus 1-3 and minus 1-3' refers to focus, it may have been the fine adjustment to get the rifle zeroed at that range.

Once the zero was achieved, presumably on some common military calibre like the 7x57 or 8x57 with the main bullet weight (possibly 154 grains in the 8x57), turning the top dial to 200 or 300 yards(?) or metres should have compensated for the drop at those distances.

Though the gunsmith should have kept the reticle centred at 100 metres, as the dial is wound to the greater distances, it will move lower in the field of view - only a problem if you think it is

Any windage adjustment needed would normally have been done in the mounts, of course.

If you were to employ this scope, the range settings might be of some use with the calibres above and others like 308 Win and .30-06 - but mounting it properly in the original way might cost $1000 or more.

I own several of them. The screw on the dial is a set screw and it just keeps the elevation fixed for a predetermined distance and load. Windage was adjusted through drifting the bases. These scopes were used on the early H&H rifles. I hope that helps some.
Steve

Yes, Steve, that's what I expected.

What do you think the 'plus 1-3 and minus 1-3' means?

Not sure on those, mine are more straight forward, just 100-200-300 etc.

thank you Sambarman and Steve When I first looked through the scope it was out of focus a bit blurry,the -3 to plus 3 was turned past to what would be a -4 so I held on to the scope and twisted it it seemed tight but then it turned and I lined the mark with zero and the scope was clear as a bell so as you mentioned about the top pin I am going to turn it out a bit and set the dial to 100 as it is currently on 300 and shoot it sorry for the response delay I was out of town again thanks for the response and yes Steve it is a Holland Royal

Thank you, too, 2barrel - I love to hear about these great old scopes.

So, since the -3 +3 was the focus, initial zeroing would have to be almost completely in the mounts - and I can think of no one better than H&H to do it.

You might glean that these issues are a hobby-horse of mine. You see, scopes before 'constantly centred reticles' were much more mechanically stable, gave relatively better fields of view and much less tunnel vision. (By the 1960s many German scopes had no more separation of the fields than you get when looking off the edge of wire-rimmed spectacles.)

Such scopes often needed shims or mounts milled by gunsmiths but the costs were worthwhile and no big deal to H&H, so skilled in fitting and regulating double rifles. It is a pity the London makers didn't lean on Zeiss/Hensoldt to keep making some reticle-movement scopes when they finally succumbed to image-movement in 1975 - Swarovski made both types for some years, at least. (Some other brands like Nickel, Kahles and Unertl hung out for a few more years, even though Redfield and Weaver's 1956-'62 patents had lapsed, and Pecar kept the faith until stumps in 2006.)