Greetings,

Wishing a Happy Thanksgiving to ASSRA members.

I have a German target rifle made in the late 1800's. I am trying to better understand the details of the rear aperture sight. The attached pictures show a front, rear and side view. My questions are as follows:

1) What is the purpose of the narrow vertical slit in the plate that allows the diopter to be attached to the rear aperture sight assembly? Is it to be used without the diopter in place?

2) The sight is missing the vertical adjustment screw, which threads into the tang. As best as I can tell the screw would have a very coarse metric thread. My estimation is M6.5 x 3.0. Is this a typical thread for that period?

3) The rifle has a front sight blade, a two leaf mid-sight on the barrel and a rear aperture at the tang. In sighting the rifle on a target, I assume all three need to be aligned. Would the purpose of the diopter then be to mainly increase the depth of field to bring the target and sights in better focus?

4) A diopter, elevation screw and key/wrench for adjustment would be needed to restore the rear sight. In old posts I see the names of Mr. Loos and Mr. Heilman mentioned as individuals that do this kind of work. Are there any others that I should consider contacting?

Thank you for your consideration.

Cheater open sight according to the NMLRA. Big discussion several years ago.
This sight and a big hat about equal to an aperture sight.
Not legal for ML open sight competition, but appears widely used in Europe.
Chuck

Speaking from experience, a correct-size clock winding key will work just fine.  I'll also throw in that if there are any old jewelry stores near you, check with them.  Many such used to do clock repairs and if so they often have a literal shoe box full of old keys that they will let you paw through and choose one or two, for which you'll be charged a pittance, if anything.

Bill Lawrence

if you can't find a key--------drill a piece of bar to the across falts dimension required. File another piece of fairly decent steel to the square section required and taper it near the end.
Heat the drilled piece to cherry red. hammer the tapered bar into the hole.
You have just made your own key.
Fred

If you mess around with German rifles enough, get a pair of the keys shown, one for even numbered sizes and one for odd.  Covers all the bases.

Most larget clock shops carry them.  Failing that there's always amazon.