Central Bisley sight.

gettin old aint gor sissys and as we age we appreciate more what we missed in life , 

i shot three gun for a couple years till it was apparent i couldnt keep up with all the young ones , i had fun collecting all my guns - i still have them but dont get them out often enough , particularly the shotgun - its more home defence these days , 

i shot sporting clays with a bunch of friends and on a league , but since my friends have fallen away from it so have i , i would still go do that again just because i loved the idea of different targets after every move , its really a fun sport , 

now i shoot cowboy action but im seeing a decline in my ability , ill keep doing it because i love shooting the old guns and i like reloading my own ammo , i dont care anymore where i place - im in the largest age group in CAS but ive always shot age category and im not a gamer that would shoot an obscure category just to win , i know some that do , its never been my intent to be "the winner" at any cost , i want to enjoy what i do and those i do it with , ill keep doing it till i cant , 

all that said , and i didnt mean to bore anyone or sound like im whining , im not , i started late and im sorry i did but ive enjoyed what little ive had , 

Set the original rear sight and the new sight to 200 yards. Check the all three sights (front, rear and dioptre) align. Then raise the rear to 800 or the equivalent of the maximum elevation of the dioptre. 

then check that the 3 sighting points are still aligned. To ensure that the dioptre has not moved left or right. You may need some very minor adjustment of the baseplate if the alignment is off.