Rolf,

this particular rifle is very accurate and the sights are good - if you look under the link above in this thread, you will see a target.
Have been able (once) to put 5 shots in one inch over 60 m, but this was a black/white target. Actual problems are not group size, but seeing contrast in less than ideal light, and aiming correctly (for instance, I find it much more difficult to keep same height of impact than to avoid errors to left or right). And changing light conditions have a lot of effect. Actually I was practising for quite a while till I had the confidence.
My practical limit would be the distance where I still hit the proverbial Bierfilz (beer mat) any time.

I am also playing with a Ferlach cape gun 11.15x52R (shortened .43 Mauser case) but have more problems here. Haven't found the right bullet yet, and the sights are not so clear to see. No good groups with Swiss black powder yet, but SR4759 looks promising.

Waidmannsheil to your Mauser!
Fuhrmann